Document and Entity Information - shares	3 Months Ended
Document and Entity Information - shares	Mar. 31, 2019	May 01, 2019
Document and Entity Information
Entity Registrant Name	Kosmos Energy Ltd.
Entity Central Index Key	0001509991
Document Type	10-Q
Document Period End Date	Mar. 31, 2019
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		401,303,816
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 134,423	$ 173,515
Restricted cash	537	4,527
Receivables:
Joint interest billings, net	54,580	64,572
Oil sales	103,597	48,164
Related party	11	5,580
Other	27,991	21,690
Inventories	87,295	84,827
Prepaid expenses and other	58,404	68,040
Derivatives	17,289	38,785
Total current assets	484,127	509,700
Property and equipment:
Oil and gas properties, net	3,900,584	3,444,864
Other property, net	14,219	14,837
Property and equipment, net	3,914,803	3,459,701
Other assets:
Equity method investment	0	51,896
Restricted cash	7,574	7,574
Long-term receivables - joint interest billings	20,670	19,002
Deferred financing costs, net of accumulated amortization of $12,719 and $12,065 at March 31, 2019 and December 31, 2018, respectively	8,283	8,937
Deferred tax assets	33,144	14,004
Derivatives	8,243	14,312
Other	25,012	3,063
Total assets	4,501,856	4,088,189
Current liabilities:
Accounts payable	174,073	176,540
Accrued liabilities	187,941	195,596
Derivatives	51,713	12,172
Total current liabilities	413,727	384,308
Long-term liabilities:
Long-term debt, net	2,195,826	2,120,547
Derivatives	13,306	10,181
Asset retirement obligations	268,535	145,336
Deferred tax liabilities	704,122	477,179
Other long-term liabilities	29,747	9,160
Total long-term liabilities	3,211,536	2,762,403
Stockholders’ equity:
Preference shares, $0.01 par value; 200,000,000 authorized shares; zero issued at March 31, 2019 and December 31, 2018	0	0
Common stock, $0.01 par value; 2,000,000,000 authorized shares; 445,525,116 and 442,914,675 issued at March 31, 2019 and December 31, 2018, respectively	4,455	4,429
Additional paid-in capital	2,329,244	2,341,249
Accumulated deficit	(1,220,099)	(1,167,193)
Treasury stock, at cost, 44,263,269 and 44,263,269 shares at March 31, 2019 and December 31, 2018, respectively	(237,007)	(237,007)
Total stockholders’ equity	876,593	941,478
Total liabilities and stockholders’ equity	$ 4,501,856	$ 4,088,189

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Deferred financing costs, accumulated amortization	$ 12,719	$ 12,065
Preference shares, par value (in dollars per share)	$ 0.01	$ 0.01
Preference shares, authorized shares (in shares)	200,000,000	200,000,000
Preference shares, issued shares (in shares)	0	0
Common shares, par value (in dollars per share)	$ 0.01	$ 0.01
Common shares, authorized shares (in shares)	2,000,000,000	2,000,000,000
Common shares, issued shares (in shares)	445,525,116	442,914,675
Treasury stock shares (in shares)	44,263,269	44,263,269

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands		3 Months Ended
	Feb. 25, 2019	Mar. 31, 2019	Mar. 31, 2018
Revenues and other income:
Oil and gas revenue		$ 296,790	$ 127,196
Other income, net		0	(19)
Total revenues and other income		296,790	127,177
Costs and expenses:
Oil and gas production		79,799	46,768
Facilities insurance modifications, net		(20,021)	8,449
Exploration expenses		30,344	21,193
General and administrative		35,908	21,883
Depletion, depreciation and amortization		118,095	54,277
Interest and other financing costs, net		35,041	25,694
Derivatives, net		77,085	38,478
(Gain) loss on equity method investments, net		0	(18,696)
Other expenses, net		2,119	3,705
Total costs and expenses		358,370	201,751
Loss before income taxes		(61,580)	(74,574)
Income tax benefit		(8,674)	(24,348)
Net loss		$ (52,906)	$ (50,226)
Net loss per share:
Basic (in dollars per share)		$ (0.13)	$ (0.13)
Diluted (in dollars per share)		$ (0.13)	$ (0.13)
Weighted average number of shares used to compute net loss per share:
Basic (in shares)		401,164	395,600
Diluted (in shares)		401,164	395,600
Dividends declared per common stock (in dollars per share)	$ 0.0452	$ 0.0452	$ 0

CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Common Shares	Additional Paid-in Capital	Accumulated Deficit	Treasury Stock
Balance at the beginning (in shares) at Dec. 31, 2017		398,599
Balance at the beginning at Dec. 31, 2017	$ 897,112	$ 3,986	$ 2,014,525	$ (1,073,202)	$ (48,197)
Increase (Decrease) in Shareholders' Equity
Equity-based compensation	8,392		8,392
Restricted stock awards and units (in shares)		6,380
Restricted stock awards and units	0	$ 64	(64)
Purchase of treasury stock / tax withholdings	(11,874)		(11,364)		(510)
Net loss	(50,226)			(50,226)
Balance at the end (in shares) at Mar. 31, 2018		404,979
Balance at the end at Mar. 31, 2018	843,404	$ 4,050	2,011,489	(1,123,428)	(48,707)
Balance at the beginning (in shares) at Dec. 31, 2018		442,915
Balance at the beginning at Dec. 31, 2018	941,478	$ 4,429	2,341,249	(1,167,193)	(237,007)
Increase (Decrease) in Shareholders' Equity
Dividends ($0.0452 per share)	(18,744)		(18,744)
Equity-based compensation	8,744		8,744
Restricted stock awards and units (in shares)		2,610
Restricted stock awards and units	0	$ 26	(26)
Purchase of treasury stock / tax withholdings	(1,979)		(1,979)
Net loss	(52,906)			(52,906)
Balance at the end (in shares) at Mar. 31, 2019		445,525
Balance at the end at Mar. 31, 2019	$ 876,593	$ 4,455	$ 2,329,244	$ (1,220,099)	$ (237,007)

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References + Details

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Operating activities
Net loss	$ (52,906)	$ (50,226)
Adjustments to reconcile net loss to net cash used in operating activities:
Depletion, depreciation and amortization	120,482	56,717
Deferred income taxes	(39,833)	(24,697)
Unsuccessful well costs	(160)	43
Change in fair value of derivatives	73,807	38,966
Cash settlements on derivatives, net (including $(7.3) million and $(19.7) million on commodity hedges during 2019 and 2018)	(3,576)	(20,397)
Equity-based compensation	8,441	8,017
Loss on extinguishment of debt	0	4,056
Distributions in excess of equity in earnings	0	5,234
Other	10,647	(478)
Changes in assets and liabilities:
(Increase) decrease in receivables	(47,219)	67,937
(Increase) decrease in inventories	2,212	(7,849)
(Increase) decrease in prepaid expenses and other	12,597	(2,439)
Decrease in accounts payable	(59,331)	(3,554)
Decrease in accrued liabilities	(42,508)	(88,346)
Net cash used in operating activities	(17,347)	(17,016)
Investing activities
Oil and gas assets	(78,377)	(34,712)
Other property	(1,071)	(1,757)
Return of investment from KTIPI	0	41,070
Net cash provided by (used in) investing activities	(79,448)	4,601
Financing activities
Borrowings under long-term debt	175,000	0
Payments on long-term debt	(100,000)	0
Purchase of treasury stock / tax withholdings	(1,980)	(11,874)
Dividends	(18,147)	0
Deferred financing costs	(1,160)	(24,969)
Net cash provided by (used in) financing activities	53,713	(36,843)
Net decrease in cash, cash equivalents and restricted cash	(43,082)	(49,258)
Cash, cash equivalents and restricted cash at beginning of period	185,616	304,986
Cash, cash equivalents and restricted cash at end of period	142,534	255,728
Cash paid for:
Interest, net of capitalized interest	40,536	33,280
Income taxes	$ 10,438	$ 21,243

Organization	3 Months Ended
Organization	Mar. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	Organization Kosmos Energy Ltd. changed its jurisdiction of incorporation from Bermuda to the State of Delaware (the "Redomestication") in December 2018. As part of the Redomestication, we transferred all of our equity interests in Kosmos Energy Holdings to a new, wholly-owned subsidiary, Kosmos Energy Delaware Holdings, LLC, a Delaware limited liability company. As a holding company, Kosmos Energy Ltd.’s management operations are conducted through a wholly-owned subsidiary, Kosmos Energy, LLC. The terms “Kosmos,” the “Company,” “we,” “us,” “our,” “ours,” and similar terms refer to Kosmos Energy Ltd. and its wholly-owned subsidiaries, unless the context indicates otherwise. Kosmos is a full-cycle deepwater independent oil and gas exploration and production company focused along the Atlantic Margins. Our key assets include production offshore Ghana, Equatorial Guinea and U.S. Gulf of Mexico, as well as a world-class gas development offshore Mauritania and Senegal. We also maintain a sustainable exploration program balanced between proven basin infrastructure-led exploration (Equatorial Guinea and U.S. Gulf of Mexico), emerging basins (Mauritania, Senegal and Suriname) and frontier basins (Cote d'Ivoire, Namibia and Sao Tome and Principe). Kosmos is listed on the New York Stock Exchange and London Stock Exchange and is traded under the ticker symbol KOS. Kosmos is engaged in a single line of business, which is the exploration and production of oil and natural gas. Substantially all of our long-lived assets and all of our product sales are related to operations in four geographic areas: Ghana, Equatorial Guinea, Mauritania/Senegal and U.S. Gulf of Mexico. In addition we have exploration activities in other countries in the Atlantic Margins.

Accounting Policies

3 Months Ended

Mar. 31, 2019

Accounting Policies [Abstract]

Accounting Policies

General

The interim-period financial information presented in the consolidated financial statements included in this report is unaudited and, in the opinion of management, includes all adjustments of a normal recurring nature necessary to present fairly the consolidated financial position as of March 31, 2019, the changes in the consolidated statements of stockholders’ equity for the three months ended March 31, 2019, the consolidated results of operations for the three months ended March 31, 2019 and 2018, and the consolidated cash flows for the three months ended March 31, 2019 and 2018. The results of the interim periods shown in this report are not necessarily indicative of the final results to be expected for the full year. The consolidated financial statements were prepared in accordance with the requirements of the Securities and Exchange Commission (“SEC”) for interim reporting. As permitted under those rules, certain notes or other financial information that are normally required by Generally Accepted Accounting Principles in the United States of America (“GAAP”) have been condensed or omitted from these interim consolidated financial statements. These consolidated financial statements and the accompanying notes should be read in conjunction with our audited consolidated financial statements for the year ended December 31, 2018, included in our annual report on Form 10-K.

Reclassifications

Certain prior period amounts have been reclassified to conform with the current presentation. Such reclassifications had no impact on our reported net loss, current assets, total assets, current liabilities, total liabilities, stockholders’ equity or cash flows. Additionally, as a result of our outstanding shares in KTIPI being transferred for an undivided interest in the Ceiba Field and Okume Complex (effective January 1, 2019), our previously reported equity method investment in KTIPI has been allocated to the respective assets and liabilities on a relative fair value basis. See Note 7 — Equity Method Investments for additional information.

Cash, Cash Equivalents and Restricted Cash



	March 31, 2019		December 31, 2018
	(In thousands)
Cash and cash equivalents	$	134,423	$	173,515
Restricted cash - current	537		4,527
Restricted cash - long-term	7,574		7,574
Total cash, cash equivalents and restricted cash shown in the consolidated statement of cash flows	$	142,534	$	185,616

Cash and cash equivalents include demand deposits and funds invested in highly liquid instruments with original maturities of three months or less at the date of purchase.

In accordance with certain of our petroleum contracts, we have posted letters of credit related to performance guarantees for our minimum work obligations. These letters of credit are cash collateralized in accounts held by us and as such are classified as restricted cash. Upon completion of the minimum work obligations and/or entering into the next phase of the petroleum contract, the requirement to post the existing letters of credit will be satisfied and the cash collateral will be released. However, additional letters of credit may be required should we choose to move into the next phase of certain of our petroleum contracts.

Inventories

Inventories consisted of $78.1 million and $83.4 million of materials and supplies and $9.2 million and $1.4 million of hydrocarbons as of March 31, 2019 and December 31, 2018, respectively. The Company’s materials and supplies inventory primarily consists of casing and wellheads and is stated at the lower of cost, using the weighted average cost method, or net realizable value.

Hydrocarbon inventory is carried at the lower of cost, using the weighted average cost method, or net realizable value. Hydrocarbon inventory costs include expenditures and other charges incurred in bringing the inventory to its existing condition. Selling expenses and general and administrative expenses are reported as period costs and excluded from inventory costs.

Leases (Policy applicable beginning January 1, 2019)

We account for leases in accordance with ASC Topic 842, Leases, (“ASC 842”). We determine if an arrangement is a lease at contract inception. A lease exists when a contract conveys to the customer the right to control the use of identified property, plant, or equipment for a period of time in exchange for consideration. The definition of a lease embodies two conditions: (1) there is an identified asset in the contract that is land or a depreciable asset (i.e., property, plant, and equipment), and (2) the customer has the right to control the use of the identified asset.

In the normal course of business, the Company enters into various lease agreements for real estate and equipment related to its exploration, development and production activities that are currently accounted for as operating leases. Operating Leases are included in Other assets and Accrued liabilities and Other long-term liabilities on our Consolidated Balance Sheets. The lease liabilities are initially and subsequently measured at the present value of the unpaid lease payments at the lease commencement date.

Key estimates and judgments include how we determined (1) the discount rate we use to discount the unpaid lease payments to present value, (2) lease term and (3) lease payments.

ASC 842 requires a lessee to discount its unpaid lease payments using the interest rate implicit in the lease or, if that rate cannot be readily determined, its incremental borrowing rate. As most of our leases where we are the lessee do not provide an implicit rate, we use our incremental borrowing rate based on the information available at commencement date in determining the present value of lease payments. Our incremental borrowing rate for a lease is the rate of interest we would have to pay on a collateralized basis to borrow an amount equal to the lease payments under similar terms.


2.	The lease term for all of our leases includes the noncancellable period of the lease plus any additional periods covered by either an option to extend (or not to terminate) the lease that we are reasonably certain to exercise, or an option to extend (or not to terminate) the lease controlled by the lessor.

Lease payments included in the measurement of the lease asset or liability comprise the following: fixed payments (including in-substance fixed payments), variable payments that depend on index or rate, and the exercise price of a lessee option to purchase the underlying asset if we are reasonably certain to exercise. Amounts expected to be payable under residual value guarantee are also lease payments included in the measurement of the lease liability.

The Right-of-use ("ROU") asset is initially measured at cost, which comprises the initial amount of the lease liability adjusted for lease payments made at or before the lease commencement date, plus any initial direct costs incurred less any lease incentives received.

For operating leases, the ROU asset is subsequently measured throughout the lease term at the carrying amount of the lease liability, plus initial direct costs, plus (minus) any prepaid (accrued) lease payments, less the unamortized balance of lease incentives received. Lease expense for lease payments is recognized on a straight-line basis over the lease term.

We monitor for events or changes in circumstances that require a reassessment of a lease. When a reassessment results in the remeasurement of a lease liability, a corresponding adjustment is made to the carrying amount of the corresponding ROU asset unless doing so would reduce the carrying amount of the ROU asset to an amount less than zero. In that case, the amount of the adjustment that would result in a negative ROU asset balance is recorded in profit or loss.

We have lease agreements which include lease and nonlease components. We have elected to combine lease and nonlease components for all lease contracts.

We have elected not to recognize ROU assets and lease liabilities for all short-term leases that have a lease term of 12 months or less. We recognize the lease payments associated with our short-term leases as an expense on a straight-line basis over the lease term.

We adopted ASU 2016-02 using a modified retrospective transition approach as of the effective date as permitted by the amendments in ASU 2018-11, which provides an alternative modified retrospective transition method. As a result, we were not required to adjust our comparative period financial information for effects of the standard or make the new required lease disclosures for periods before the date of adoption (i.e. January 1, 2019). We have elected to adopt the package of transition practical expedients and, therefore, have not reassessed (1) whether existing or expired contracts contain a lease, (2) lease classification for existing or expired leases or (3) the accounting for initial direct costs that were previously capitalized. We did not elect the practical expedient to use hindsight for leases existing at the adoption date. Further, we do not expect the amendments in ASU 2018-01: Land Easement Practical Expedient to have an effect on us because we do not enter into land easement arrangements.

Revenue Recognition

We recognize revenues on the volumes sold to a purchaser. The volumes sold may be more or less than the volumes to which we are entitled based on our ownership interest in the property. These differences result in a condition known in the industry as a production imbalance. A receivable or liability is recognized only to the extent that we have an imbalance on a specific property greater than the expected remaining proved reserves on such property. As of March 31, 2019 and December 31, 2018, we had no oil and gas imbalances recorded in our consolidated financial statements.

Our oil and gas revenues are recognized when production has been sold to a purchaser at a fixed or determinable price, title has transferred and collectability is probable. Certain revenues are based on provisional price contracts which contain an embedded derivative that is required to be separated from the host contract for accounting purposes. The host contract is the receivable from oil sales at the spot price on the date of sale. The embedded derivative, which is not designated as a hedge, is marked to market through oil and gas revenue each period until the final settlement occurs, which generally is limited to the month after the sale.

Oil and gas revenue is composed of the following:



	Three Months Ended March 31,
	2019		2018
	(In thousands)
Revenues from contract with customers - Equatorial Guinea	$	89,115	$	—
Revenues from contracts with customers - Ghana	119,330		128,037
Revenues from contracts with customers - U.S. Gulf of Mexico	85,067		—
Provisional oil sales contracts	3,278		(841		)
Oil and gas revenue	$	296,790	$	127,196

Concentration of Credit Risk

Our revenue can be materially affected by current economic conditions and the price of oil. However, based on the current demand for crude oil and the fact that alternative purchasers are readily available, we believe that the loss of our marketing agent and/or any of the purchasers identified by our marketing agent would not have a long‑term material adverse effect on our financial position or results of international operations. For our U.S. Gulf of Mexico operations, crude oil and natural gas are transported to customers using third-party pipelines. For the three months ended March 31, 2019, revenue from Phillips 66 Company made up approximately 22% of our total consolidated revenue and was included in our U.S. Gulf of Mexico segment.

Recent Accounting Standards

Recently Adopted

In February 2016, the FASB issued ASU 2016-02, “Leases (Topic 842).” ASU 2016-02 was issued to increase transparency and comparability across organizations by recognizing substantially all leases on the balance sheet through the concept of right-of-use lease assets and liabilities. Under current accounting guidance, lessees do not recognize lease assets or liabilities for leases classified as operating leases. The ASU is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years with early adoption permitted. In July 2018, the FASB issued ASU 2018-11, which added a transition option permitting entities to apply the provisions of the new standard at its adoption date instead of the earliest comparative period presented in the consolidated financial statements. Under this transition option, comparative reporting would not be required, and the provisions of the standard would be applied prospectively to leases in effect at the date of adoption. The Company adopted the guidance prospectively during the first quarter of 2019. As part of our adoption, we elected not to reassess historical lease classification, recognize short-term leases on our balance sheet, nor separate lease and non-lease components for our real estate leases. The adoption and implementation of this ASU resulted in a $21.7 million increase in assets and liabilities related to our leasing activities which primarily consists of office leases. Our adoption of ASU 2016-02 did not impact retained earnings or other components of equity as of December 31, 2018.

Acquisitions and Divestitures	3 Months Ended
Acquisitions and Divestitures	Mar. 31, 2019
Business Combinations [Abstract]
Acquisitions and Divestitures	Acquisitions and Divestitures 2019 Transactions During the first quarter of 2019, we entered into a petroleum contract covering Marine XXI block with the Republic of the Congo, subject to customary governmental approvals. Upon approval, we will hold an 85% participating interest and are the operator. The Congolese national oil company, SPNC, has a 15% carried participating interest during the exploration period. Should a commercial discovery be made, SNPC's 15% carried interest will convert to a participating interest of at least 15%. The petroleum contract covers approximately 2,350 square kilometers, with a first exploration period of four years and include a work program to acquire and interpret 2,200 square kilometers of 3D seismic. There are two optional exploration phases, each for a period of three years, which are subject to additional work program commitments. During the first quarter of 2019, Kosmos farmed-in to 18 BP-owned blocks in the Garden Banks area of the deepwater U.S. Gulf of Mexico. In addition, Kosmos can earn an interest in three BP blocks in other areas of the deepwater U.S. Gulf of Mexico. This should allow Kosmos to execute projects that can be tied back to existing infrastructure. Kosmos is the designated operator and plans to commence drilling operations on the first well in Garden Banks block 492, the Resolution prospect, in 2019. During the first quarter of 2019, Kosmos executed a farm-in agreement with Chevron covering the right to earn an interest in a strategic block in the deepwater U.S. Gulf of Mexico. This agreement allows Kosmos another opportunity to execute its deepwater U.S. Gulf of Mexico strategy of lower risk prospects with the potential for subsea development near existing infrastructure. Kosmos will be designated operator and plans to commence drilling operations in 2019. During the first quarter of 2019, Kosmos was one of the most active participants in the U.S. Gulf of Mexico Lease Sale 252 in which we were the apparent high bidder on nine blocks. 2018 Transactions In March 2018, as part of our alliance with BP, we entered into petroleum contracts covering Blocks 10 and 13 with the Democratic Republic of Sao Tome and Principe and BP. We have a 35% participating interest in the blocks and the operator, BP, holds a 50% participating interest. The national petroleum agency, ANP-STP has a 15% carried interest in the blocks through exploration. The petroleum contracts cover approximately 13,600 square kilometers, with a first exploration period of four years from the effective date (March 2018). The exploration periods can be extended an additional four years at our election subject to fulfilling specific work obligations. The first exploration period work programs include a 13,500 square kilometer 3D seismic acquisition across the two blocks. In June 2018, we completed a farm-in agreement with a subsidiary of Ophir for Block EG-24, offshore Equatorial Guinea, whereby we acquired a 40% non-operated participating interest. As part of the agreement, we reimbursed a portion of Ophir's previously incurred exploration costs and agreed to carry Ophir's share of the costs of a planned 3D seismic program as well as pay a disproportionate share of the well commitment should we enter the second exploration sub-period. The petroleum contract covers approximately 3,500 square kilometers, with a first exploration period of three years from the effective date (March 2018) which can be extended up to four additional years at our election subject to fulfilling specific work obligations. The first exploration period work program includes a 3,000 square kilometer 3D seismic acquisition requirement which was completed in November 2018. In March 2019, we acquired Ophir's remaining interest in the block, which resulted in Kosmos owning an 80% interest in Block EG-24. The Equatorial Guinean national oil company, GEPetrol, has a 20% carried participating interest during the exploration period. Should a commercial discovery be made, GEPetrol's 20% carried interest will convert to a 20% participating interest. In August 2018, we closed a farm-out agreement with Trident, whereby they acquired a 40% participating interest in blocks EG-21, S, and W, offshore Equatorial Guinea, resulting in a $7.7 million gain. After giving effect to the farm-out agreement, we hold a 40% participating interest and are the operator in all three blocks. The Equatorial Guinean national oil company, GEPetrol, has a 20% carried participating interest during the exploration period. Should a commercial discovery be made, GEPetrol's 20% carried interest will convert to a 20% participating interest. The petroleum contracts cover approximately 6,000 square kilometers, with a first exploration period of five years from the effective date (March 2018). The first exploration period consists of two sub-periods of three and two years, respectively. The first exploration sub-period work program includes a 6,000 square kilometer 3D seismic acquisition requirement across the three blocks, which was completed in 2018. In September 2018, we completed the acquisition of DGE, a deepwater company operating in the U.S. Gulf of Mexico, from First Reserve Corporation and other shareholders for a total consideration of $1.275 billion, comprised of $952.6 million in cash and $307.9 million in Kosmos common stock and $14.9 million of transaction related costs. We funded the cash portion of the purchase price using cash on hand and drawings under our existing credit facilities. The DGE acquisition was accounted for under the asset acquisition method and there were no changes from the purchase price allocation disclosed in the Company's Annual Report on Form 10-K for the year ended December 31, 2018. In October 2018, Kosmos entered into a strategic exploration alliance with Shell to jointly explore in Southern West Africa. Initially the alliance will focus on Namibia where Kosmos has completed a farm-in to Shell's acreage in PEL 39, and Sao Tome and Principe where we have entered into exclusive negotiations for Shell to take an interest in a portion of Kosmos’ acreage. As part of the alliance, the two companies intend to jointly evaluate opportunities in adjacent geographies. This alliance is consistent with Kosmos’ strategy of partnering with supermajors to leverage complementary skill sets. Shell has deep expertise in carbonate plays, while Kosmos brings significant knowledge of the Cretaceous in West Africa. Furthermore, by working with Shell, Kosmos has a partner with the expertise to efficiently move exploration successes through the development stage.

Joint Interest Billings and Related Party Receivables	3 Months Ended
Joint Interest Billings and Related Party Receivables	Mar. 31, 2019
Joint Interest Billings
Joint Interest Billings and Related Party Receivables	Joint Interest Billings and Related Party Receivables The Company’s joint interest billings consist of receivables from partners with interests in common oil and gas properties operated by the Company. Joint interest billings are classified on the face of the consolidated balance sheets as current and long-term receivables based on when collection is expected to occur. In 2014, GNPC notified us and our block partners of its request for the contractor group to pay GNPC’s 5% share of the Tweneboa, Enyenra and Ntomme (“TEN”) development costs. The block partners are being reimbursed for such costs plus interest out of a portion of GNPC’s TEN production revenues. As of March 31, 2019 and December 31, 2018, the current portions of the joint interest billing receivables due from GNPC for the TEN fields development costs were $14.0 million and $14.0 million, respectively, and the long-term portions were $15.2 million and $14.0 million, respectively. The Company's related party receivables consists primarily of receivables from Trident which, until January 2019, we shared a 50% interest in KTIPI. As of December 31, 2018 the balance due from Trident consists of $5.6 million related to joint interest billings for the exploration blocks and Kosmos' support of KTIPI operations. Subsequent to the unwind of KTIPI, Trident is no longer considered a related party.

Property and Equipment

3 Months Ended

Mar. 31, 2019

Property, Plant and Equipment [Abstract]

Property and Equipment

Property and equipment is stated at cost and consisted of the following:



	March 31, 2019			December 31, 2018
	(In thousands)
Oil and gas properties:
Proved properties	$	3,177,330		$	2,773,276
Unproved properties	857,009			759,472
Support equipment and facilities	1,528,308			1,463,213
Total oil and gas properties	5,562,647			4,995,961
Accumulated depletion	(1,662,063		)	(1,551,097		)
Oil and gas properties, net	3,900,584			3,444,864

Other property	52,815			51,987
Accumulated depreciation	(38,596		)	(37,150		)
Other property, net	14,219			14,837

Property and equipment, net	$	3,914,803		$	3,459,701

We recorded depletion expense of $111.0 million and $51.6 million for the three months ended March 31, 2019 and 2018, respectively. The increase to oil and gas properties primarily relates to proportionate consolidation resulting from the unwind of our equity method investment in Equatorial Guinea. See Note 7 — Equity Method Investments for additional information.

Suspended Well Costs

3 Months Ended

Mar. 31, 2019

Oil and Gas Exploration and Production Industries Disclosures [Abstract]

Suspended Well Costs

The following table reflects the Company’s capitalized exploratory well costs on completed wells as of and during the three months ended March 31, 2019. The table excludes nil costs that were capitalized and subsequently expensed during the same period.



	March 31, 2019
	(In thousands)
Beginning balance	$	367,665
Additions to capitalized exploratory well costs pending the determination of proved reserves	2,410
Reclassification due to determination of proved reserves	—
Capitalized exploratory well costs charged to expense	—
Ending balance	$	370,075

The following table provides an aging of capitalized exploratory well costs based on the date drilling was completed and the number of projects for which exploratory well costs have been capitalized for more than one year since the completion of drilling:



	March 31, 2019		December 31, 2018
	(In thousands, except well counts)
Exploratory well costs capitalized for a period of one year or less	$	—	$	—
Exploratory well costs capitalized for a period of one to two years	127,532		299,253
Exploratory well costs capitalized for a period of three years	242,543		68,412
Ending balance	$	370,075	$	367,665
Number of projects that have exploratory well costs that have been capitalized for a period greater than one year	3		3

As of March 31, 2019, the projects with exploratory well costs capitalized for more than one year since the completion of drilling are related to the Greater Tortue Ahmeyim Unit, which crosses the Mauritania and Senegal maritime border, the BirAllah discovery (formerly known as the Marsouin discovery) in Block C8 offshore Mauritania, and the Yakaar and Teranga discoveries in the Cayar Offshore Profond block offshore Senegal.

Greater Tortue Ahmeyim Unit — In May 2015, we completed the Tortue-1 exploration well in Block C8 offshore Mauritania, which encountered hydrocarbon pay. Two additional wells have been drilled in the Greater Tortue Discovery area, Ahmeyim-2 in Mauritania and Guembeul-1 in Senegal. We completed a drill stem test on the Tortue‑1 well in August 2017, which confirmed the production capabilities of the Greater Tortue Ahmeyim Unit. Data acquired from the drill stem test was used to further optimize field development and to refine process design parameters critical to the FEED process. In December 2018, we made a final investment decision to develop Phase 1 of the Greater Tortue Ahmeyim Unit.

BirAllah Discovery — In November 2015, we completed the Marsouin-1 exploration well (renamed BirAllah) in the northern part of Block C8 offshore Mauritania, which encountered hydrocarbon pay. Following additional evaluation, a decision regarding commerciality is expected to be made. An exploration well is planned for the nearby Orca prospect during 2019, which will help delineate the available resource in the region to refine the development plans for the BirAllah discovery.

Yakaar and Teranga Discoveries — In May 2016, we completed the Teranga-1 exploration well in the Cayar Offshore Profond block offshore Senegal, which encountered hydrocarbon pay. In June 2017, we completed the Yakaar-1 exploration well in the Cayar Offshore Profond block offshore Senegal, which encountered hydrocarbon pay. In November 2017, an integrated Yakaar-Teranga appraisal plan was submitted. An appraisal well is scheduled in 2019 to further evaluate the discovery. Following additional evaluation, a decision regarding commerciality is expected to be made.

Equity Method Investments

3 Months Ended

Mar. 31, 2019

Equity Method Investments and Joint Ventures [Abstract]

Equity Method Investments

Equatorial Guinea

As part of our acquisition of KTIPI, a corporate joint venture entity in which we owned a 50% interest, we acquired an indirect participating interest in Block G offshore Equatorial Guinea. The objective of this transaction was to acquire the Ceiba Field and Okume Complex with the intent to optimize production and increase reserves. Below is a summary of financial information for KTIPI presented on a 100% basis.



	December 31,
	2018
	(In thousands)
Assets
Total current assets	$	149,950
Property and equipment, net	271,627
Other assets	21
Total assets	$	421,598

Liabilities and stockholders' equity
Total current liabilities	$	226,311
Total long-term liabilities	536,178
Shareholders' equity:
Total shareholders' equity	(340,891		)
Total liabilities and shareholders' equity	$	421,598



	Three Months Ended March 31, 2018
	(In thousands)
Revenues and other income:
Oil and gas revenue	$	246,354
Other income	287
Total revenues and other income	246,641

Costs and expenses:
Oil and gas production	51,700
Depletion, depreciation and amortization	54,070
Other expenses, net	(79		)
Total costs and expenses	105,691

Income before income taxes	140,950
Income tax expense	49,632
Net income	$	91,318

Kosmos' share of net income	$	45,659
Basis difference amortization(1)	26,963
Equity in earnings - KTIPI	$	18,696

______________________________________


(1)	The basis difference, which is associated with oil and gas properties and subject to amortization, has been allocated to the Ceiba Field and Okume Complex. We amortize the basis difference using the unit-of-production method.

With an effective date of January 1, 2019, our outstanding shares in KTIPI were transferred to Trident in exchange for a 40.375% undivided interest in the Ceiba Field and Okume Complex. As a result, our interest in the Ceiba Field and Okume Complex is accounted for under the proportionate consolidation method of accounting going forward. This transaction was accounted for as an asset acquisition. The carrying value of the equity method investment was allocated to the undivided interest acquired and net working capital based on the estimated relative fair value of the acquired assets.

The estimated fair value measurements of oil and gas assets acquired and asset retirement obligations liabilities assumed are based on inputs that are not observable in the market and therefore represent Level 3 inputs. The fair value of oil and gas properties and asset retirement obligations were measured using the discounted cash flow technique of valuation. Significant inputs to the valuation of oil and gas properties include estimates of: (i) reserves, (ii) future operating and development costs, (iii) future commodity prices, (iv) future plugging and abandonment costs, (v) estimated future cash flows, and (vi) a market-based weighted average cost of capital rate. These fair value estimates were used to allocate the carrying value of the equity method investment to our balance sheet on a relative fair value basis.



	Carrying Value Allocation (in thousands)
Assets acquired:
Proved oil and gas properties	$	372,144
Unproved oil and gas properties	103,909
Prepaids and other	7,273
Total assets acquired	$	483,326

Liabilities assumed:
Asset retirement obligations	$	114,395
Deferred tax liabilities	247,636
Accrued liabilities and other	69,399
Total liabilities assumed	$	431,430

Carrying value:
Equity method investment carrying value at December 31, 2018	$	51,896

Debt

3 Months Ended

Mar. 31, 2019

Debt Disclosure [Abstract]

Debt



	March 31, 2019			December 31, 2018
	(In thousands)
Outstanding debt principal balances:
Facility	$	1,500,000		$	1,325,000
Corporate Revolver	225,000			325,000
Senior Secured Notes	525,000			525,000
Total	2,250,000			2,175,000
Unamortized deferred financing costs and discounts(1)	(54,174		)	(54,453		)
Long-term debt, net	$	2,195,826		$	2,120,547

__________________________________


(1)	Includes $42.2 million and $40.5 million of unamortized deferred financing costs related to the Facility and $12.0 million and $14.0 million of unamortized deferred financing costs and discounts related to the Senior Secured Notes as of March 31, 2019 and December 31, 2018, respectively.

Facility

In February 2018, the Company amended and restated the Facility with a total commitment of $1.5 billion from a number of financial institutions with additional commitments up to $0.5 billion being available if the existing financial institutions increase their commitments or if commitments from new financial institutions are added. In August 2018, the Company entered into letter agreements with two existing financial institutions, which obligated the two financial institutions to provide the Company, upon the Company's election, with an additional commitment of $200 million in the aggregate under the Facility. The borrowing base calculation includes value related to the Jubilee, TEN, Ceiba and Okume fields. In March 2019, following the lender's annual redetermination, the available borrowing base under our Facility was $1.7 billion. The Facility supports our oil and gas exploration, appraisal and development programs and corporate activities. As part of the debt refinancing in February 2018, the repayment of borrowings under the existing facility attributable to financial institutions that did not participate in the amended Facility was accounted for as an extinguishment of debt, and $4.1 million of existing unamortized debt issuance costs and deferred interest attributable to those participants was expensed in interest and other financing costs, net in the first quarter of 2018. As of March 31, 2019, we have $42.2 million of unamortized issuance costs related to the Facility, which will be amortized over the remaining term of the Facility. As of March 31, 2019, borrowings under the Facility totaled $1,500.0 million and the undrawn availability under the Facility was $200.0 million, which was reduced to $100 million following the Senior Notes issuance in April 2019.

The Facility provides a revolving credit and letter of credit facility. The availability period for the revolving credit facility expires one month prior to the final maturity date. The letter of credit facility expires on the final maturity date. The available facility amount is subject to borrowing base constraints and, beginning on March 31, 2022, outstanding borrowings will be constrained by an amortization schedule. The Facility has a final maturity date of March 31, 2025. As of March 31, 2019, we had no letters of credit issued under the Facility.

We were in compliance with the financial covenants contained in the Facility as of March 31, 2019 (the most recent assessment date). The Facility contains customary cross default provisions.

Corporate Revolver

In August 2018, we amended and restated the Corporate Revolver from a number of financial institutions, maintaining the borrowing capacity at $400.0 million, extending the maturity date from November 2018 to May 2022 and lowering the margin 100 basis points to 5%. This results in lower commitment fees on the undrawn portion of the total commitments, which is 30% per annum of the respective margin. The Corporate Revolver is available for general corporate purposes and for oil and gas exploration, appraisal and development programs.

As of March 31, 2019, borrowings under the Corporate Revolver totaled $225.0 million and the undrawn availability under the Corporate Revolver was $175.0 million. As of March 31, 2019, we have $8.3 million of net deferred financing costs related to the Corporate Revolver, which will be amortized over its remaining term. We were in compliance with the financial covenants contained in the Corporate Revolver as of March 31, 2019 (the most recent assessment date). The Corporate Revolver contains customary cross default provisions.

Revolving Letter of Credit Facility

We have a revolving letter of credit facility agreement (“LC Facility”), which matures in July 2019. In December 2018, the LC Facility size was voluntarily reduced to $20.0 million based on the expiration of several large outstanding letters of credit. As of March 31, 2019, there were six outstanding letters of credit totaling $9.4 million under the LC Facility. The LC Facility contains customary cross default provisions.

7.875% Senior Secured Notes due 2021

During August 2014, the Company issued $300.0 million of 7.875% Senior Secured Notes due 2021 (the "Senior Secured Notes") and received net proceeds of approximately $292.5 million after deducting discounts, commissions and deferred financing costs. The Company used the net proceeds to repay a portion of the outstanding indebtedness under the Facility and for general corporate purposes.

During April 2015, we issued an additional $225.0 million of Senior Secured Notes and received net proceeds of $206.8 million after deducting discounts, commissions and other expenses. We used the net proceeds to repay a portion of the outstanding indebtedness under the Facility and for general corporate purposes. The additional $225.0 million of Senior Secured Notes had identical terms to the initial $300.0 million of Senior Secured Notes, other than the date of issue, the initial price, the first interest payment date and the first date from which interest accrued.

In April 2019, all of the Senior Secured Notes were redeemed for $543.8 million, including accrued interest and the early redemption premium. The redemption resulted in a $22.9 million loss on extinguishment of debt, which will be included in Interest and other financing costs, net on the Consolidated Statement of Operations during the second quarter.

7.125% Senior Notes due 2026

In April 2019, the Company issued $650.0 million of 7.125% Senior Notes (the "Senior Notes") and received net proceeds of approximately $640.0 million after deducting commissions and other expenses. We used the net proceeds to redeem all of the Senior Secured Notes, repay a portion of the outstanding indebtedness under the Corporate Revolver and pay fees and expenses related to the redemption, repayment and the issuance of the Senior Notes.

The Senior Notes mature on April 4, 2026. We will pay interest in arrears on the Senior Notes each April 4 and October 4, commencing on October 4, 2019. The Senior Notes are senior, unsecured obligations of Kosmos Energy Ltd. and rank equal in right of payment with all of its existing and future senior indebtedness (including all borrowings under the Corporate Revolver) and rank effectively junior in right of payment to all of its existing and future secured indebtedness (including all borrowings under the Facility). The Senior Notes are guaranteed on a senior, unsecured basis by certain subsidiaries owning the Company's Gulf of Mexico assets, and on a subordinated, unsecured basis by certain subsidiaries that guarantee the Facility.

At any time prior to April 4, 2022, and subject to certain conditions, the Company may, on one or more occasions, redeem up to 40% of the original principal amount of the Senior Notes with an amount not to exceed the net cash proceeds of certain equity offerings at a redemption price of 107.1% of the outstanding principal amount of the Senior Notes, together with accrued and unpaid interest and premium, if any, to, but excluding, the date of redemption. Additionally, at any time prior to April 4, 2022 the Company may, on any one or more occasions, redeem all or a part of the Senior Notes at a redemption price equal to 100%, plus any accrued and unpaid interest, and plus a “make-whole” premium. On or after April 4, 2022, the Company may redeem all or a part of the Senior Notes at the redemption prices (expressed as percentages of principal amount) set forth below plus accrued and unpaid interest:



Year	Percentage
On or after April 4, 2022, but before April 4, 2023	103.6	%
On or after April 4, 2023, but before April 4, 2024	101.8	%
On or after April 4, 2024 and thereafter	100.0	%

We may also redeem the Senior Notes in whole, but not in part, at any time if changes in tax laws impose certain withholding taxes on amounts payable on the Senior Notes at a price equal to the principal amount of the Senior Notes plus accrued interest and additional amounts, if any, as may be necessary so that the net amount received by each holder after any withholding or deduction on payments of the Senior Notes will not be less than the amount such holder would have received if such taxes had not been withheld or deducted.

Upon the occurrence of a change of control triggering event as defined under the Senior Notes indenture, the Company will be required to make an offer to repurchase the Senior Notes at a repurchase price equal to 101% of the principal amount, plus accrued and unpaid interest to, but excluding, the date of repurchase.

If we sell assets, under certain circumstances outlined in the Senior Notes indenture, we will be required to use the net proceeds to make an offer to purchase the Senior Notes at an offer price in cash in an amount equal to 100% of the principal amount of the Senior Notes, plus accrued and unpaid interest to, but excluding, the repurchase date.

The Senior Notes indenture restricts our ability and the ability of our restricted subsidiaries to, among other things: incur or guarantee additional indebtedness, create liens, pay dividends or make distributions in respect of capital stock, purchase or redeem capital stock, make investments or certain other restricted payments, sell assets, enter into agreements that restrict the ability of our subsidiaries to make dividends or other payments to us, enter into transactions with affiliates, or effect certain consolidations, mergers or amalgamations. These covenants are subject to a number of important qualifications and exceptions. Certain of these covenants will be terminated if the Senior Notes are assigned an investment grade rating by both Standard & Poor’s Rating Services and Fitch Ratings Inc. and no default or event of default has occurred and is continuing.

At March 31, 2019, the estimated repayments of debt during the five fiscal year periods and thereafter are as follows:



	Payments Due by Year
	Total		2019(2)		2020		2021		2022		2023		Thereafter
	(In thousands)
Principal debt repayments(1)	$	2,250,000	$	—	$	—	$	799,800	$	509,200	$	271,600	$	669,400

__________________________________

(1)

Includes the scheduled principal maturities for the $525.0 million aggregate principal amount of Senior Secured Notes issued in August 2014 and April 2015, borrowings under the Facility and the Corporate Revolver. The scheduled maturities of debt related to the Facility are based on, as of March 31, 2019, our level of borrowings and our estimated future available borrowing base commitment levels in future periods. Any increases or decreases in the level of borrowings or increases or decreases in the available borrowing base would impact the scheduled maturities of debt during the next five years and thereafter. In April 2019, the Senior Secured Notes were redeemed with the proceeds from the issuance of the Senior Notes which increased the borrowings to $650 million and extended the maturity date to 2026.


(2)	Represents payments for the period April 1, 2019 through December 31, 2019.

Interest and other financing costs, net

Interest and other financing costs, net incurred during the periods is comprised of the following:



	Three Months Ended March 31,
	2019			2018
	(In thousands)
Interest expense	$	38,172		$	24,893
Amortization—deferred financing costs	2,387			2,440
Loss on extinguishment of debt	—			4,056
Capitalized interest	(7,251		)	(4,820		)
Deferred interest	836			(1,256		)
Interest income	(652		)	(948		)
Other, net	1,549			1,329
Interest and other financing costs, net	$	35,041		$	25,694

Derivative Financial Instruments

3 Months Ended

Mar. 31, 2019

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Derivative Financial Instruments

We use financial derivative contracts to manage exposures to commodity price and interest rate fluctuations. We do not hold or issue derivative financial instruments for trading purposes.

We manage market and counterparty credit risk in accordance with our policies and guidelines. In accordance with these policies and guidelines, our management determines the appropriate timing and extent of derivative transactions. We have included an estimate of non-performance risk in the fair value measurement of our derivative contracts as required by ASC 820 — Fair Value Measurements and Disclosures.

Oil Derivative Contracts

The following table sets forth the volumes in barrels underlying the Company’s outstanding oil derivative contracts and the weighted average prices per Bbl for those contracts as of March 31, 2019. Volumes and weighted average prices are net of any offsetting derivative contracts entered into.



				Weighted Average Price per Bbl
				Net Deferred
				Premium
Term	Type of Contract	Index	MBbl	Payable/(Receivable)		Swap		Sold Put		Floor		Ceiling
2019:
Apr — Dec	Three-way collars	Dated Brent	7,880	$	1.17	$	—	$	43.81	$	53.33	$	73.57
Apr — Dec	Sold calls(1)	Dated Brent	688	—		—		—		—		80.00
Apr — Dec	Swaps	NYMEX WTI	1,224	—		52.22		—		—		—
Apr — Jun	Collars	NYMEX WTI	169	—		—		—		57.77		63.70
Apr — Dec	Collars	Argus LLS	750	—		—		—		60.00		88.75
2020:
Jan — Dec	Three-way collars	Dated Brent	4,500	$	0.58	$	—	$	45.00	$	57.50	$	81.91
Jan — Dec	Sold calls(1)(2)	Dated Brent	8,000	$	1.17	$	—	$	—	$	—	$	85.00

__________________________________


(1)	Represents call option contracts sold to counterparties to enhance other derivative positions.


(2)	Deferred premium payable to be paid April 1, 2019 — December 31, 2019.

In April 2019, we entered into three-way collar contracts for 1.5 MMBbl from January 2020 through December 2020 with a sold put price of $45.00 per barrel, a floor price of $57.50 per barrel and a ceiling price of $75.00 per barrel. The contracts are indexed to Dated Brent prices.

The following tables disclose the Company’s derivative instruments as of March 31, 2019 and December 31, 2018 and gain/(loss) from derivatives during the three months ended March 31, 2019 and 2018, respectively:



		Estimated Fair Value
		Asset (Liability)
Type of Contract	Balance Sheet Location	March 31, 2019			December 31, 2018
		(In thousands)
Derivatives not designated as hedging instruments:
Derivative assets:
Commodity(1)	Derivatives assets—current	$	17,289		$	38,785
Commodity(2)	Derivatives assets—long-term	8,243			14,312
Derivative liabilities:
Commodity(3)	Derivatives liabilities—current	(51,713		)	(12,172		)
Commodity(4)	Derivatives liabilities—long-term	(13,306		)	(10,181		)
Total derivatives not designated as hedging instruments		$	(39,487	)	$	30,744

__________________________________


(1)	Includes zero and $0.4 million as of March 31, 2019 and December 31, 2018, respectively which represents our provisional oil sales contract. Also, includes net deferred premiums payable of $5.5 million and $1.6 million related to commodity derivative contracts as of March 31, 2019 and December 31, 2018, respectively.


(2)	Includes net deferred premiums payable of $0.1 million and $1.3 million related to commodity derivative contracts as of March 31, 2019 and December 31, 2018, respectively.


(3)	Includes net deferred premiums payable of $11.0 million and $18.0 million related to commodity derivative contracts as of March 31, 2019 and December 31, 2018, respectively.


(4)	Includes net deferred premiums payable of $2.0 million and $0.5 million related to commodity derivative contracts as of March 31, 2019 and December 31, 2018, respectively.



		Amount of Gain/(Loss)
		Three Months Ended
		March 31,
Type of Contract	Location of Gain/(Loss)	2019			2018
		(In thousands)
Derivatives not designated as hedging instruments:
Commodity(1)	Oil and gas revenue	$	3,278		$	(841	)
Commodity	Derivatives, net	(77,085		)	(38,478		)
Interest rate	Interest expense	—			353
Total derivatives not designated as hedging instruments		$	(73,807	)	$	(38,966	)

__________________________________


(1)	Amounts represent the change in fair value of our provisional oil sales contracts.

Offsetting of Derivative Assets and Derivative Liabilities

Our derivative instruments which are subject to master netting arrangements with our counterparties only have the right of offset when there is an event of default. As of March 31, 2019 and December 31, 2018, there was not an event of default and, therefore, the associated gross asset or gross liability amounts related to these arrangements are presented on the consolidated balance sheets.

Fair Value Measurements

3 Months Ended

Mar. 31, 2019

Fair Value Disclosures [Abstract]

Fair Value Measurements

In accordance with ASC Topic 820 — Fair Value Measurements and Disclosures, fair value measurements are based upon inputs that market participants use in pricing an asset or liability, which are classified into two categories: observable inputs and unobservable inputs. Observable inputs represent market data obtained from independent sources, whereas unobservable inputs reflect a company’s own market assumptions, which are used if observable inputs are not reasonably available without undue cost and effort. We prioritize the inputs used in measuring fair value into the following fair value hierarchy:


•	Level 1 — quoted prices for identical assets or liabilities in active markets.


•	Level 2 — quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable for the asset or liability and inputs derived principally from or corroborated by observable market data by correlation or other means.


•	Level 3 — unobservable inputs for the asset or liability. The fair value input hierarchy level to which an asset or liability measurement in its entirety falls is determined based on the lowest level input that is significant to the measurement in its entirety.

The following tables present the Company’s assets and liabilities that are measured at fair value on a recurring basis as of March 31, 2019 and December 31, 2018, for each fair value hierarchy level:



	Fair Value Measurements Using:
	Quoted Prices in
	Active Markets for		Significant Other			Significant
	Identical Assets		Observable Inputs			Unobservable Inputs
	(Level 1)		(Level 2)			(Level 3)		Total
	(In thousands)
March 31, 2019
Assets:
Commodity derivatives	$	—	$	25,532		$	—	$	25,532
Liabilities:
Commodity derivatives	—		(65,019		)	—		(65,019		)
Total	$	—	$	(39,487	)	$	—	$	(39,487	)
December 31, 2018
Assets:
Commodity derivatives	$	—	$	53,097		$	—	$	53,097
Liabilities:
Commodity derivatives	—		(22,353		)	—		(22,353		)
Total	$	—	$	30,744		$	—	$	30,744

The book values of cash and cash equivalents and restricted cash approximate fair value based on Level 1 inputs. Joint interest billings, oil sales and other receivables, and accounts payable and accrued liabilities approximate fair value due to the short-term nature of these instruments. Our long-term receivables, after any allowances for doubtful accounts, and other long-term assets approximate fair value. The estimates of fair value of these items are based on Level 2 inputs.

Commodity Derivatives

Our commodity derivatives represent crude oil collars, put options, call options and swaps for notional barrels of oil at fixed Dated Brent, NYMEX WTI or Argus LLS oil prices. The values attributable to our oil derivatives are based on (i) the contracted notional volumes, (ii) independent active futures price quotes for the respective index, (iii) a credit-adjusted yield curve applicable to each counterparty by reference to the credit default swap (“CDS”) market and (iv) an independently sourced estimate of volatility for respective index. The volatility estimate was provided by certain independent brokers who are active in buying and selling oil options and was corroborated by market-quoted volatility factors. The deferred premium is included in the fair market value of the commodity derivatives. See Note 9 — Derivative Financial Instruments for additional information regarding the Company’s derivative instruments.

Provisional Oil Sales

The value attributable to provisional oil sales derivatives is based on (i) the sales volumes and (ii) the difference in the independent active futures price quotes for the respective index over the term of the pricing period designated in the sales contract and the spot price on the lifting date.

Debt

The following table presents the carrying values and fair values at March 31, 2019 and December 31, 2018:



	March 31, 2019				December 31, 2018
	Carrying Value		Fair Value		Carrying Value		Fair Value
	(In thousands)
Senior Notes	$	513,006	$	535,337	$	511,873	$	525,026
Corporate Revolver	225,000		225,000		325,000		325,000
Facility	1,500,000		1,500,000		1,325,000		1,325,000
Total	$	2,238,006	$	2,260,337	$	2,161,873	$	2,175,026

The carrying value of our Senior Notes represents the principal amounts outstanding less unamortized discounts. The fair value of our Senior Notes is based on quoted market prices, which results in a Level 1 fair value measurement. The carrying value of the Facility approximates fair value since it is subject to short-term floating interest rates that approximate the rates available to us for those periods.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Equity-based Compensation

3 Months Ended

Mar. 31, 2019

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Equity-based Compensation

Restricted Stock Units

We record equity-based compensation expense equal to the fair value of share-based payments over the vesting periods of the Long Term Incentive Plan (“LTIP”) awards. We recorded compensation expense from awards granted under our LTIP of $8.4 million and $8.0 million during the three months ended March 31, 2019 and 2018, respectively. The total tax benefit was $1.3 million and $0.9 million during the three months ended March 31, 2019 and 2018, respectively. Additionally, we recorded a net tax shortfall related to equity-based compensation of $1.2 million and $0.2 million during the three months ended March 31, 2019 and 2018, respectively. The fair value of awards vested was $13.2 million and $56.6 million during the three months ended March 31, 2019 and 2018, respectively. The Company granted restricted stock units with service vesting criteria and a combination of market and service vesting criteria under the LTIP. Substantially all these grants vest over three years. Upon vesting, restricted stock units become issued and outstanding stock.

The following table reflects the outstanding restricted stock units as of March 31, 2019:



			Weighted-		Market / Service		Weighted-
	Service Vesting		Average		Vesting		Average
	Restricted Stock		Grant-Date		Restricted Stock		Grant-Date
	Units		Fair Value		Units		Fair Value
	(In thousands)				(In thousands)
Outstanding at December 31, 2018	4,115		$	6.42	6,716		$	9.02
Granted(1)	2,726		4.81		3,041		6.02
Forfeited(1)	(53	)	6.46		(275	)	10.64
Vested	(1,797	)	5.78		(1,269	)	6.36
Outstanding at March 31, 2019	4,991		5.76		8,213		8.41

__________________________________


(1)	The restricted stock units with a combination of market and service vesting criteria may vest between 0% and 200% of the originally granted units depending upon market performance conditions. Awards vesting over or under target shares of 100% results in additional shares granted or forfeited, respectively, in the period the market vesting criteria is determined.

As of March 31, 2019, total equity-based compensation to be recognized on unvested restricted stock units is $54.9 million over a weighted average period of 2.35 years. In March 2018, the board of directors approved an amendment to the LTIP to add 11.0 million shares to the plan, which was approved by our stockholders at the Annual General Meeting in June 2018. The LTIP provides for the issuance of 50.5 million shares pursuant to awards under the plan. At March 31, 2019, the Company had approximately 10.2 million shares that remain available for issuance under the LTIP.

For restricted stock units with a combination of market and service vesting criteria, the number of common shares to be issued is determined by comparing the Company’s total shareholder return with the total shareholder return of a predetermined group of peer companies over the performance period and can vest in up to 200% of the awards granted. The grant date fair value ranged from $4.83 to $12.96 per award. The Monte Carlo simulation model utilizes multiple input variables that determine the probability of satisfying the market condition stipulated in the award grant and calculates the fair value of the award. The expected volatility utilized in the model was estimated using our historical volatility and the historical volatilities of our peer companies and ranged from 44.0% to 52.0%. The risk-free interest rate was based on the U.S. treasury rate for a term commensurate with the expected life of the grant and ranged from 0.8% to 2.5%.

Income Taxes

3 Months Ended

Mar. 31, 2019

Income Tax Disclosure [Abstract]

Income Taxes

Kosmos Energy Ltd. changed its jurisdiction of incorporation from Bermuda to the State of Delaware in December 2018. The company was not subject to taxation at the parent company level for the three months ended March 31, 2018. We provide for income taxes based on the laws and rates in effect in the countries in which our operations are conducted. The relationship between our pre‑tax income or loss from continuing operations and our income tax expense or benefit varies from period to period as a result of various factors, which include changes in total pre‑tax income or loss, the jurisdictions in which our income (loss) is earned and the tax laws in those jurisdictions.

We evaluate our estimated annual effective income tax rate based on current and forecasted business results and enacted tax laws on a quarterly basis and apply this tax rate to our ordinary income or loss to calculate our estimated tax expense or benefit. The Company excludes zero tax rate and tax-exempt jurisdictions from our evaluation of the estimated annual effective income tax rate. The tax effect of discrete items are recognized in the period in which they occur at the applicable statutory tax rate.

The income tax provision consists of United States, Ghanaian income and Texas margin taxes. Beginning January 1, 2019, the income tax provision includes our Equatorial Guinean pre-tax income and income taxes. For 2018, results from operations in Equatorial Guinea is reported, net of tax, as Gain on equity method investments, net in our Consolidated Statement of Operations. Our operations in other foreign jurisdictions have a 0% effective tax rate because they reside in countries with a 0% statutory rate or we have incurred losses in those countries and have full valuation allowances against the corresponding net deferred tax assets.

Income (loss) before income taxes is composed of the following:



	Three Months Ended March 31,
	2019			2018
	(In thousands)
United States	$	(55,741	)	$	1,633
Bermuda	—			(16,071		)
Foreign—other	(5,839		)	(60,136		)
Income (loss) before income taxes	$	(61,580	)	$	(74,574	)

For the three months ended, March 31, 2019 and 2018, our effective tax rate was 14% and 33%, respectively. For the three months ended March 31, 2019 our overall effective tax rate was impacted by the difference in our 21% U.S. income tax reporting rate and the 35% statutory tax rates applicable to our Ghanaian and Equatorial Guinean operations, non-deductible and non-taxable items associated with our U.S., Ghanaian, and Equatorial Guinean operations and other losses and expenses, primarily related to exploration operations in tax-exempt jurisdictions or in taxable jurisdictions where we have valuation allowances against our deferred tax assets, and therefore, we do not realize any tax benefit on such expenses or losses.

For the three-months ended March 31, 2018, our overall effective tax rate was impacted by non-deductible and non-taxable items associated with our U.S. and Ghanaian operations and other losses and expenses, primarily related to exploration operations in tax-exempt jurisdictions or in taxable jurisdictions where we have valuation allowances against our deferred tax assets, and therefore, we do not realize any tax benefit on such expenses or losses.

The Company files income tax returns in all jurisdictions where such requirements exist, however, our primary tax jurisdictions are the United States, Ghana and Equatorial Guinea. The Company is open to Ghanaian federal income tax examinations for tax years 2014 through 2018 and in the United States, to federal income tax examinations for tax years 2015 through 2018.

As of March 31, 2019, the Company had no material uncertain tax positions. The Company’s policy is to recognize potential interest and penalties related to income tax matters in income tax expense.

Net Loss Per Share

3 Months Ended

Mar. 31, 2019

Earnings Per Share [Abstract]

Net Loss Per Share

The following table is a reconciliation between net loss and the amounts used to compute basic and diluted net loss per share and the weighted average shares outstanding used to compute basic and diluted net loss per share:



	Three Months Ended
	March 31,
	2019			2018
Numerator:
Net loss allocable to common stockholders	$	(52,906	)	$	(50,226	)
Denominator:
Weighted average number of shares outstanding:
Basic	401,164			395,600
Restricted stock units(1)	—			—
Diluted	401,164			395,600
Net loss per share:
Basic	$	(0.13	)	$	(0.13	)
Diluted	$	(0.13	)	$	(0.13	)

__________________________________


(1)	We excluded outstanding restricted stock awards and units of 8.9 million and 11.3 million for the three months ended March 31, 2019 and 2018, respectively, from the computations of diluted net loss per share because the effect would have been anti-dilutive.

Commitments and Contingencies

3 Months Ended

Mar. 31, 2019

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

From time to time, we are involved in litigation, regulatory examinations and administrative proceedings primarily arising in the ordinary course of our business in jurisdictions in which we do business. Although the outcome of these matters cannot be predicted with certainty, management believes none of these matters, either individually or in the aggregate, would have a material effect upon the Company’s financial position; however, an unfavorable outcome could have a material adverse effect on our results from operations for a specific interim period or year.

We currently have a commitment to drill one exploration well in each of Mauritania, Sao Tome and Principe, and Namibia and two exploration wells in Senegal. Our partner in Mauritania and Senegal is obligated to fund our share of the cost of the exploration wells, subject to the remaining exploration and appraisal carry covering both our Mauritania and Senegal blocks. In Sao Tome and Principe, we also have 3D seismic acquisition requirements of approximately 13,500 square kilometers.

Leases

We have commitments under operating leases primarily related to office leases. Our leases have initial lease terms ranging from one year to ten years. Certain lease agreements contain provisions for future rent increases.

The components of lease cost for the three months ended March 31 are as follows:



	Three months ended March 31, 2019
	(In thousands)
Operating lease cost	$	1,407
Short-term lease cost	5
Total lease cost	$	1,412

Other information related to operating leases at March 31, 2019, is as follows:



	March 31, 2019
(In thousands, except lease term and discount rate)
Balance sheet classifications
Other assets (right-of-use assets)	$	22,410
Accrued liabilities (current maturities of leases)	2,842
Other long-term liabilities (non-current maturities of leases)	20,884

Weighted average remaining lease term	9.1 years

Weighted average discount rate	9.9		%

The table below presents supplemental cash flow information related to leases during the three months ended March 31, 2019:



	Three months ended March 31, 2019
	(In thousands)
Operating cash flows for operating leases	$	1,223

Future minimum rental commitments under our leases at March 31, 2019, are as follows:



	Operating Leases(1)
	(In thousands)
2019(2)	$	2,078
2020	4,522
2021	3,852
2022	3,903
2023	3,916
Thereafter	19,549
Total undiscounted lease payments	$	37,820
Less: Imputed interest	(14,094		)
Total lease liabilities	$	23,726

__________________________________


(1)	Does not include purchase commitments for jointly owned fields and facilities where we are not the operator and excludes commitments for exploration activities, including well commitments, in our petroleum contracts.


(2)	Represents payments for the period from April 1, 2019 through December 31, 2019.

Performance Obligations

As of March 31, 2019 and December 31, 2018, the Company had secured performance bonds totaling $199.8 million and $200.9 million, respectively, for our supplemental bonding requirements stipulated by the BOEM and $3.7 million and $3.7 million, respectively, to another operator related to costs anticipated for the plugging and abandonment of certain wells and the removal of certain facilities in its U.S. Gulf of Mexico fields. As of March 31, 2019 and December 31, 2018, we had zero and $0.6 million, respectively, of cash collateral against these secured performance bonds which is classified as Other long term assets in our consolidated balance sheet.

In February 2019, Kosmos and BP signed Carry Advance Agreements with the national oil companies of Mauritania and Senegal which obligate us separately to finance the respective national oil company’s share of certain development costs incurred through first gas for Phase 1, currently projected in the first half of 2022. Kosmos’ total share for the two agreements combined is up to $239.7 million, which is to be repaid with interest through the national oil companies’ share of future revenues.

Dividends

On February 25, 2019, we announced our quarterly cash dividend of $0.0452 per common share. Dividends of $18.1 million were paid on March 28, 2019 to stockholders of record on March 7, 2019. On May 3, 2019, we declared our quarterly cash dividend of $0.0452 per common share for Q2 payable on June 27, 2019 to stockholders of record as of June 6, 2019.

Additional Financial Information

3 Months Ended

Mar. 31, 2019

Additional Financial Information

Additional Financial Information

Accrued Liabilities

Accrued liabilities consisted of the following:



	March 31, 2019		December 31, 2018
	(In thousands)
Accrued liabilities:
Exploration, development and production	$	102,538	$	92,613
Revenue payable	21,288		24,379
Current asset retirement obligations	5,776		6,617
Operating lease liabilities	2,842		—
General and administrative expenses	14,742		39,373
Interest	7,445		18,152
Income taxes	24,665		8,958
Taxes other than income	2,669		4,613
Derivatives	3,504		441
Other	2,472		450
	$	187,941	$	195,596

Asset Retirement Obligations

The following table summarizes the changes in the Company's asset retirement obligations:



	March 31, 2019
	(In thousands)
Asset retirement obligations:
Beginning asset retirement obligations	$	151,953
Additions associated with Equatorial Guinea - Ceiba Field and Okume Complex	114,395
Liabilities incurred during period	3,348
Liabilities settled during period	(2,232		)
Revisions in estimated retirement obligations	1,164
Accretion expense	5,683
Ending asset retirement obligations	$	274,311

Facilities Insurance Modifications, Net

Facilities insurance modifications, net consists of costs associated with the long-term solution to convert the Jubilee FPSO to a permanently spread moored facility, net of any insurance reimbursements. During the three months ended March 31, 2019 and 2018 we incurred approximately $11.0 million and $9.8 million, respectively in expenditures offset by approximately $31.0 million and $1.3 million, respectively in insurance recoveries.

Other Expenses, Net

Other expenses, net incurred during the period is comprised of the following:



	Three Months Ended March 31,
	2019			2018
	(In thousands)
Loss on disposal of inventory	$	187		$	—
Loss on ARO liability settlements	1,918			—
Disputed charges and related costs, net of recoveries	(14		)	2,335
Other, net	28			1,370
Other expenses, net	$	2,119		$	3,705

The disputed charges and related costs, net of recoveries are expenditures arising from Tullow Ghana Limited’s contract with Seadrill for use of the West Leo drilling rig once partner-approved 2016 work program objectives were concluded. Tullow charged such expenditures to the Deepwater Tano (“DT”) joint account. Kosmos disputed through arbitration that these expenditures were chargeable to the DT joint account on the basis that the Seadrill West Leo drilling rig contract was not approved by the DT operating committee pursuant to the DT Joint Operating Agreement. In July 2018, the International Chamber of Commerce ("ICC") issued its Final Award in the arbitration in favor of Kosmos. As a result, during 2018 we recovered from Tullow Ghana Limited disputed charges in the amount of $12.9 million in the form of cash payments and offsets against other unrelated joint venture costs, which include amounts previously paid under protest as well as certain costs and fees incurred pursuing the arbitration.

Business Segment Information

3 Months Ended

Mar. 31, 2019

Segment Reporting [Abstract]

Business Segment Information

Kosmos is engaged in a single line of business, which is the exploration, development and production of oil and gas. At March 31, 2019, substantially all of our long-lived assets and all of our product sales are related to operations in four geographic reporting segments: Ghana, Equatorial Guinea, Mauritania/Senegal and the U.S. Gulf of Mexico. In addition, we have exploration activities in other countries in the Atlantic Margins. To assess performance of the reporting segments, the Chief Operating Decision Maker ("CODM") reviews capital expenditures. Capital expenditures, as defined by the Company, may not be comparable to similarly titled measures used by other companies and should be considered in conjunction with our consolidated financial statements and notes thereto. Financial information for each area is presented below:



	Ghana			Equatorial Guinea		Mauritania/Senegal			U.S. Gulf of Mexico			Corporate & Other			Eliminations			Total
	(in thousands)
Three months ended March 31, 2019
Revenues and other income:
Oil and gas revenue	$	122,919		$	88,805	$	—		$	85,066		$	—		$	—		$	296,790
Other income, net	—			—		—			135			72,809			(72,944		)	—
Total revenues and other income	122,919			88,805		—			85,201			72,809			(72,944		)	296,790
Costs and expenses:
Oil and gas production	30,057			22,605		—			27,137			—			—			79,799
Facilities insurance modifications, net	(20,021		)	—		—			—			—			—			(20,021		)
Exploration expenses	52			3,171		6,442			11,194			9,485			—			30,344
General and administrative	5,956			2,045		2,287			7,393			44,205			(25,978		)	35,908
Depletion, depreciation and amortization	54,863			23,017		15			39,090			1,110			—			118,095
Interest and other financing costs, net(1)	20,653			—		(6,793		)	5,929			17,036			(1,784		)	35,041
Derivatives, net	—			—		—			31,903			45,182			—			77,085
Other expenses, net	45,100			340		229			1,592			40			(45,182		)	2,119
Total costs and expenses	136,660			51,178		2,180			124,238			117,058			(72,944		)	358,370
Income (loss) before income taxes	(13,741		)	37,627		(2,180		)	(39,037		)	(44,249		)	—			(61,580		)
Income tax expense (benefit)	(4,983		)	15,531		—			(8,206		)	(11,016		)	—			(8,674		)
Net income (loss)	$	(8,758	)	$	22,096	$	(2,180	)	$	(30,831	)	$	(33,233	)	$	—		$	(52,906	)

Consolidated capital expenditures	$	34,967		$	14,936	$	2,252		$	45,882		$	12,191		$	—		$	110,228

As of March 31, 2019
Property and equipment, net	$	1,681,317		$	470,974	$	414,035		$	1,309,412		$	39,065		$	—		$	3,914,803
Total assets	$	1,938,645		$	533,244	$	528,068		$	3,369,271		$	10,092,342		$	(11,959,714	)	$	4,501,856

______________________________________


(1)	Interest expense is recorded based on actual third-party and intercompany debt agreements. Capitalized interest is recorded on the business unit where the assets reside.



	Ghana			Equatorial Guinea(1)			Mauritania/Senegal			U.S. Gulf of Mexico(2)		Corporate & Other			Eliminations(3)			Total
	(in thousands)
Three months ended March 31, 2018
Revenues and other income:
Oil and gas revenue	$	127,196		$	123,177		$	—		$	—	$	—		$	(123,177	)	$	127,196
Other income, net	(18		)	143			—			—		65,060			(65,204		)	(19		)
Total revenues and other income	127,178			123,320			—			—		65,060			(188,381		)	127,177
Costs and expenses:
Oil and gas production	46,768			25,850			—			—		—			(25,850		)	46,768
Facilities insurance modifications, net	8,449			—			—			—		—			—			8,449
Exploration expenses	224			869			3,198			—		16,902			—			21,193
General and administrative	5,253			985			1,291			—		39,111			(24,757		)	21,883
Depletion, depreciation and amortization	53,351			53,998			15			—		911			(53,998		)	54,277
Interest and other financing costs, net(4)	21,254			(1		)	(3,921		)	—		10,146			(1,784		)	25,694
Derivatives, net	—			—			—			—		38,478			—			38,478
(Gain) loss on equity method investments, net	—			—			—			—		—			(18,696		)	(18,696		)
Other expenses, net	40,809			121			1			—		1,254			(38,480		)	3,705
Total costs and expenses	176,108			81,822			584			—		106,802			(163,565		)	201,751
Income (loss) before income taxes	(48,930		)	41,498			(584		)	—		(41,742		)	(24,816		)	(74,574		)
Income tax expense (benefit)	(24,408		)	24,816			—			—		60			(24,816		)	(24,348		)
Net income (loss)	$	(24,522	)	$	16,682		$	(584	)	$	—	$	(41,802	)	$	—		$	(50,226	)

Consolidated capital expenditures	$	18,102		$	6,891		$	3,256		$	—	$	29,380		$	—		$	57,629

As of March 31, 2018
Property and equipment, net	$	1,868,283		$	7,931		$	385,386		$	—	$	44,937		$	—		$	2,306,537
Total assets	$	2,165,726		$	214,546		$	499,082		$	—	$	8,516,046		$	(8,364,872	)	$	3,030,528

______________________________________


(1)	Includes our proportionate share of our equity method investment in KTIPI, including our basis difference which is reflected in depletion, depreciation and amortization for the three months ended March 31, 2018, except for capital expenditures. See Note 7 - Equity Method Investments for additional information regarding our equity method investments.


(2)	No activity prior to September 14, 2018, the DGE acquisition date.


(3)	Includes elimination of proportionate consolidation amounts recorded for KTIPI to reconcile to (Gain) loss on equity method investments, net as reported in the consolidated statements of operations.


(4)	Interest expense is recorded based on actual third-party and intercompany debt agreements. Capitalized interest is recorded on the business unit where the assets reside.



	Three Months Ended March 31,
	2019			2018
	(In thousands)
Consolidated capital expenditures:
Consolidated Statements of Cash Flows - Investing activities:
Oil and gas assets	$	78,377		$	34,712
Other property	1,071			1,757
Adjustments:
Changes in capital accruals	14,925			4,684
Exploration expense, excluding unsuccessful well costs(1)	30,504			21,150
Capitalized interest	(7,251		)	(4,820		)
Other	(7,398		)	146
Total consolidated capital expenditures	$	110,228		$	57,629

______________________________________


(1)	Unsuccessful well costs are included in oil and gas assets when incurred.

Accounting Policies (Policies)

3 Months Ended

Mar. 31, 2019

Accounting Policies [Abstract]

General

Reclassifications

Cash, Cash Equivalents and Restricted Cash

Cash and cash equivalents include demand deposits and funds invested in highly liquid instruments with original maturities of three months or less at the date of purchase.

Inventories

The Company’s materials and supplies inventory primarily consists of casing and wellheads and is stated at the lower of cost, using the weighted average cost method, or net realizable value.

Inventories

Leases (Policy applicable beginning January 1, 2019)

Key estimates and judgments include how we determined (1) the discount rate we use to discount the unpaid lease payments to present value, (2) lease term and (3) lease payments.


2.	The lease term for all of our leases includes the noncancellable period of the lease plus any additional periods covered by either an option to extend (or not to terminate) the lease that we are reasonably certain to exercise, or an option to extend (or not to terminate) the lease controlled by the lessor.

We have lease agreements which include lease and nonlease components. We have elected to combine lease and nonlease components for all lease contracts.

Revenue Recognition

Concentration of Credit Risk

Recent Accounting Standards

Recently Adopted

Accounting Policies (Tables)

3 Months Ended

Mar. 31, 2019

Accounting Policies [Abstract]

Schedule of cash and cash equivalents



	March 31, 2019		December 31, 2018
	(In thousands)
Cash and cash equivalents	$	134,423	$	173,515
Restricted cash - current	537		4,527
Restricted cash - long-term	7,574		7,574
Total cash, cash equivalents and restricted cash shown in the consolidated statement of cash flows	$	142,534	$	185,616

Schedule of oil and gas revenue

Oil and gas revenue is composed of the following:



	Three Months Ended March 31,
	2019		2018
	(In thousands)
Revenues from contract with customers - Equatorial Guinea	$	89,115	$	—
Revenues from contracts with customers - Ghana	119,330		128,037
Revenues from contracts with customers - U.S. Gulf of Mexico	85,067		—
Provisional oil sales contracts	3,278		(841		)
Oil and gas revenue	$	296,790	$	127,196

Property and Equipment (Tables)

3 Months Ended

Mar. 31, 2019

Property, Plant and Equipment [Abstract]

Schedule of property and equipment

Property and equipment is stated at cost and consisted of the following:



	March 31, 2019			December 31, 2018
	(In thousands)
Oil and gas properties:
Proved properties	$	3,177,330		$	2,773,276
Unproved properties	857,009			759,472
Support equipment and facilities	1,528,308			1,463,213
Total oil and gas properties	5,562,647			4,995,961
Accumulated depletion	(1,662,063		)	(1,551,097		)
Oil and gas properties, net	3,900,584			3,444,864

Other property	52,815			51,987
Accumulated depreciation	(38,596		)	(37,150		)
Other property, net	14,219			14,837

Property and equipment, net	$	3,914,803		$	3,459,701

Suspended Well Costs (Tables)

3 Months Ended

Mar. 31, 2019

Oil and Gas Exploration and Production Industries Disclosures [Abstract]

Schedule of capitalized exploratory well costs



	March 31, 2019
	(In thousands)
Beginning balance	$	367,665
Additions to capitalized exploratory well costs pending the determination of proved reserves	2,410
Reclassification due to determination of proved reserves	—
Capitalized exploratory well costs charged to expense	—
Ending balance	$	370,075

Schedule of aging of capitalized exploratory well costs and number of projects for which exploratory well costs were capitalized for more than one year



	March 31, 2019		December 31, 2018
	(In thousands, except well counts)
Exploratory well costs capitalized for a period of one year or less	$	—	$	—
Exploratory well costs capitalized for a period of one to two years	127,532		299,253
Exploratory well costs capitalized for a period of three years	242,543		68,412
Ending balance	$	370,075	$	367,665
Number of projects that have exploratory well costs that have been capitalized for a period greater than one year	3		3

Equity Method Investments (Tables)

3 Months Ended

Mar. 31, 2019

Equity Method Investments and Joint Ventures [Abstract]

Summary of financial information of KTIPI

Below is a summary of financial information for KTIPI presented on a 100% basis.



	December 31,
	2018
	(In thousands)
Assets
Total current assets	$	149,950
Property and equipment, net	271,627
Other assets	21
Total assets	$	421,598

Liabilities and stockholders' equity
Total current liabilities	$	226,311
Total long-term liabilities	536,178
Shareholders' equity:
Total shareholders' equity	(340,891		)
Total liabilities and shareholders' equity	$	421,598



	Three Months Ended March 31, 2018
	(In thousands)
Revenues and other income:
Oil and gas revenue	$	246,354
Other income	287
Total revenues and other income	246,641

Costs and expenses:
Oil and gas production	51,700
Depletion, depreciation and amortization	54,070
Other expenses, net	(79		)
Total costs and expenses	105,691

Income before income taxes	140,950
Income tax expense	49,632
Net income	$	91,318

Kosmos' share of net income	$	45,659
Basis difference amortization(1)	26,963
Equity in earnings - KTIPI	$	18,696

______________________________________


(1)	The basis difference, which is associated with oil and gas properties and subject to amortization, has been allocated to the Ceiba Field and Okume Complex. We amortize the basis difference using the unit-of-production method.

Schedule of asset acquisition

These fair value estimates were used to allocate the carrying value of the equity method investment to our balance sheet on a relative fair value basis.



	Carrying Value Allocation (in thousands)
Assets acquired:
Proved oil and gas properties	$	372,144
Unproved oil and gas properties	103,909
Prepaids and other	7,273
Total assets acquired	$	483,326

Liabilities assumed:
Asset retirement obligations	$	114,395
Deferred tax liabilities	247,636
Accrued liabilities and other	69,399
Total liabilities assumed	$	431,430

Carrying value:
Equity method investment carrying value at December 31, 2018	$	51,896

Debt (Tables)

3 Months Ended

Mar. 31, 2019

Debt Disclosure [Abstract]

Schedule of debt



	March 31, 2019			December 31, 2018
	(In thousands)
Outstanding debt principal balances:
Facility	$	1,500,000		$	1,325,000
Corporate Revolver	225,000			325,000
Senior Secured Notes	525,000			525,000
Total	2,250,000			2,175,000
Unamortized deferred financing costs and discounts(1)	(54,174		)	(54,453		)
Long-term debt, net	$	2,195,826		$	2,120,547

__________________________________


(1)	Includes $42.2 million and $40.5 million of unamortized deferred financing costs related to the Facility and $12.0 million and $14.0 million of unamortized deferred financing costs and discounts related to the Senior Secured Notes as of March 31, 2019 and December 31, 2018, respectively.

Schedule of redemption prices (expressed as percentages of principal amount) of all or a part of the Senior Notes

On or after April 4, 2022, the Company may redeem all or a part of the Senior Notes at the redemption prices (expressed as percentages of principal amount) set forth below plus accrued and unpaid interest:



Year	Percentage
On or after April 4, 2022, but before April 4, 2023	103.6	%
On or after April 4, 2023, but before April 4, 2024	101.8	%
On or after April 4, 2024 and thereafter	100.0	%

Schedule of estimated repayments of debt

At March 31, 2019, the estimated repayments of debt during the five fiscal year periods and thereafter are as follows:



	Payments Due by Year
	Total		2019(2)		2020		2021		2022		2023		Thereafter
	(In thousands)
Principal debt repayments(1)	$	2,250,000	$	—	$	—	$	799,800	$	509,200	$	271,600	$	669,400

__________________________________

(1)


(2)	Represents payments for the period April 1, 2019 through December 31, 2019.

Schedule of interest and other financing costs, net

Interest and other financing costs, net incurred during the periods is comprised of the following:



	Three Months Ended March 31,
	2019			2018
	(In thousands)
Interest expense	$	38,172		$	24,893
Amortization—deferred financing costs	2,387			2,440
Loss on extinguishment of debt	—			4,056
Capitalized interest	(7,251		)	(4,820		)
Deferred interest	836			(1,256		)
Interest income	(652		)	(948		)
Other, net	1,549			1,329
Interest and other financing costs, net	$	35,041		$	25,694

- Definition

Tabular disclosure of long-debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the entity, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28541-108399

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21506-112644

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(e),(f))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28551-108399

Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21521-112644

Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21538-112644

Reference 8: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

Reference 9: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

Reference 10: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21475-112644

+ Details

Derivative Financial Instruments (Tables)

3 Months Ended

Mar. 31, 2019

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Schedule of oil derivative contracts



				Weighted Average Price per Bbl
				Net Deferred
				Premium
Term	Type of Contract	Index	MBbl	Payable/(Receivable)		Swap		Sold Put		Floor		Ceiling
2019:
Apr — Dec	Three-way collars	Dated Brent	7,880	$	1.17	$	—	$	43.81	$	53.33	$	73.57
Apr — Dec	Sold calls(1)	Dated Brent	688	—		—		—		—		80.00
Apr — Dec	Swaps	NYMEX WTI	1,224	—		52.22		—		—		—
Apr — Jun	Collars	NYMEX WTI	169	—		—		—		57.77		63.70
Apr — Dec	Collars	Argus LLS	750	—		—		—		60.00		88.75
2020:
Jan — Dec	Three-way collars	Dated Brent	4,500	$	0.58	$	—	$	45.00	$	57.50	$	81.91
Jan — Dec	Sold calls(1)(2)	Dated Brent	8,000	$	1.17	$	—	$	—	$	—	$	85.00

__________________________________


(1)	Represents call option contracts sold to counterparties to enhance other derivative positions.


(2)	Deferred premium payable to be paid April 1, 2019 — December 31, 2019.

Schedule of derivative instruments by balance sheet location



		Estimated Fair Value
		Asset (Liability)
Type of Contract	Balance Sheet Location	March 31, 2019			December 31, 2018
		(In thousands)
Derivatives not designated as hedging instruments:
Derivative assets:
Commodity(1)	Derivatives assets—current	$	17,289		$	38,785
Commodity(2)	Derivatives assets—long-term	8,243			14,312
Derivative liabilities:
Commodity(3)	Derivatives liabilities—current	(51,713		)	(12,172		)
Commodity(4)	Derivatives liabilities—long-term	(13,306		)	(10,181		)
Total derivatives not designated as hedging instruments		$	(39,487	)	$	30,744

__________________________________


(1)	Includes zero and $0.4 million as of March 31, 2019 and December 31, 2018, respectively which represents our provisional oil sales contract. Also, includes net deferred premiums payable of $5.5 million and $1.6 million related to commodity derivative contracts as of March 31, 2019 and December 31, 2018, respectively.


(2)	Includes net deferred premiums payable of $0.1 million and $1.3 million related to commodity derivative contracts as of March 31, 2019 and December 31, 2018, respectively.


(3)	Includes net deferred premiums payable of $11.0 million and $18.0 million related to commodity derivative contracts as of March 31, 2019 and December 31, 2018, respectively.


(4)	Includes net deferred premiums payable of $2.0 million and $0.5 million related to commodity derivative contracts as of March 31, 2019 and December 31, 2018, respectively.

Schedule of derivative instruments by location of gain/(loss)



		Amount of Gain/(Loss)
		Three Months Ended
		March 31,
Type of Contract	Location of Gain/(Loss)	2019			2018
		(In thousands)
Derivatives not designated as hedging instruments:
Commodity(1)	Oil and gas revenue	$	3,278		$	(841	)
Commodity	Derivatives, net	(77,085		)	(38,478		)
Interest rate	Interest expense	—			353
Total derivatives not designated as hedging instruments		$	(73,807	)	$	(38,966	)

__________________________________


(1)	Amounts represent the change in fair value of our provisional oil sales contracts.

Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2019

Fair Value Disclosures [Abstract]

Schedule of Company's assets and liabilities that are measured at fair value on a recurring basis



	Fair Value Measurements Using:
	Quoted Prices in
	Active Markets for		Significant Other			Significant
	Identical Assets		Observable Inputs			Unobservable Inputs
	(Level 1)		(Level 2)			(Level 3)		Total
	(In thousands)
March 31, 2019
Assets:
Commodity derivatives	$	—	$	25,532		$	—	$	25,532
Liabilities:
Commodity derivatives	—		(65,019		)	—		(65,019		)
Total	$	—	$	(39,487	)	$	—	$	(39,487	)
December 31, 2018
Assets:
Commodity derivatives	$	—	$	53,097		$	—	$	53,097
Liabilities:
Commodity derivatives	—		(22,353		)	—		(22,353		)
Total	$	—	$	30,744		$	—	$	30,744

Schedule of carrying values and fair values of financial instruments that are not carried at fair value

The following table presents the carrying values and fair values at March 31, 2019 and December 31, 2018:



	March 31, 2019				December 31, 2018
	Carrying Value		Fair Value		Carrying Value		Fair Value
	(In thousands)
Senior Notes	$	513,006	$	535,337	$	511,873	$	525,026
Corporate Revolver	225,000		225,000		325,000		325,000
Facility	1,500,000		1,500,000		1,325,000		1,325,000
Total	$	2,238,006	$	2,260,337	$	2,161,873	$	2,175,026

Equity-based Compensation (Tables)

3 Months Ended

Mar. 31, 2019

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Schedule of plan activity

The following table reflects the outstanding restricted stock units as of March 31, 2019:



			Weighted-		Market / Service		Weighted-
	Service Vesting		Average		Vesting		Average
	Restricted Stock		Grant-Date		Restricted Stock		Grant-Date
	Units		Fair Value		Units		Fair Value
	(In thousands)				(In thousands)
Outstanding at December 31, 2018	4,115		$	6.42	6,716		$	9.02
Granted(1)	2,726		4.81		3,041		6.02
Forfeited(1)	(53	)	6.46		(275	)	10.64
Vested	(1,797	)	5.78		(1,269	)	6.36
Outstanding at March 31, 2019	4,991		5.76		8,213		8.41

__________________________________


(1)	The restricted stock units with a combination of market and service vesting criteria may vest between 0% and 200% of the originally granted units depending upon market performance conditions. Awards vesting over or under target shares of 100% results in additional shares granted or forfeited, respectively, in the period the market vesting criteria is determined.

Net Loss Per Share (Tables)

3 Months Ended

Mar. 31, 2019

Earnings Per Share [Abstract]

Schedule of reconciliation between net income (loss) and amounts used to compute basic and diluted EPS



	Three Months Ended
	March 31,
	2019			2018
Numerator:
Net loss allocable to common stockholders	$	(52,906	)	$	(50,226	)
Denominator:
Weighted average number of shares outstanding:
Basic	401,164			395,600
Restricted stock units(1)	—			—
Diluted	401,164			395,600
Net loss per share:
Basic	$	(0.13	)	$	(0.13	)
Diluted	$	(0.13	)	$	(0.13	)

__________________________________


(1)	We excluded outstanding restricted stock awards and units of 8.9 million and 11.3 million for the three months ended March 31, 2019 and 2018, respectively, from the computations of diluted net loss per share because the effect would have been anti-dilutive.

Commitments and Contingencies (Tables)

3 Months Ended

Mar. 31, 2019

Commitments and Contingencies Disclosure [Abstract]

Schedule of Components of Lease Costs and Cash Flow Information

The table below presents supplemental cash flow information related to leases during the three months ended March 31, 2019:



	Three months ended March 31, 2019
	(In thousands)
Operating cash flows for operating leases	$	1,223

The components of lease cost for the three months ended March 31 are as follows:



	Three months ended March 31, 2019
	(In thousands)
Operating lease cost	$	1,407
Short-term lease cost	5
Total lease cost	$	1,412

Schedule of Other Information on Leases

Other information related to operating leases at March 31, 2019, is as follows:



	March 31, 2019
(In thousands, except lease term and discount rate)
Balance sheet classifications
Other assets (right-of-use assets)	$	22,410
Accrued liabilities (current maturities of leases)	2,842
Other long-term liabilities (non-current maturities of leases)	20,884

Weighted average remaining lease term	9.1 years

Weighted average discount rate	9.9		%

Schedule of Future Minimum Rental Commitments

Future minimum rental commitments under our leases at March 31, 2019, are as follows:



	Operating Leases(1)
	(In thousands)
2019(2)	$	2,078
2020	4,522
2021	3,852
2022	3,903
2023	3,916
Thereafter	19,549
Total undiscounted lease payments	$	37,820
Less: Imputed interest	(14,094		)
Total lease liabilities	$	23,726

__________________________________


(1)	Does not include purchase commitments for jointly owned fields and facilities where we are not the operator and excludes commitments for exploration activities, including well commitments, in our petroleum contracts.


(2)	Represents payments for the period from April 1, 2019 through December 31, 2019.

Additional Financial Information (Tables)

3 Months Ended

Mar. 31, 2019

Additional Financial Information

Schedule of accrued liabilities

Accrued liabilities consisted of the following:



	March 31, 2019		December 31, 2018
	(In thousands)
Accrued liabilities:
Exploration, development and production	$	102,538	$	92,613
Revenue payable	21,288		24,379
Current asset retirement obligations	5,776		6,617
Operating lease liabilities	2,842		—
General and administrative expenses	14,742		39,373
Interest	7,445		18,152
Income taxes	24,665		8,958
Taxes other than income	2,669		4,613
Derivatives	3,504		441
Other	2,472		450
	$	187,941	$	195,596

Schedule of changes in asset retirement obligations

The following table summarizes the changes in the Company's asset retirement obligations:



	March 31, 2019
	(In thousands)
Asset retirement obligations:
Beginning asset retirement obligations	$	151,953
Additions associated with Equatorial Guinea - Ceiba Field and Okume Complex	114,395
Liabilities incurred during period	3,348
Liabilities settled during period	(2,232		)
Revisions in estimated retirement obligations	1,164
Accretion expense	5,683
Ending asset retirement obligations	$	274,311

Schedule of other expenses, net incurred

Other expenses, net incurred during the period is comprised of the following:



	Three Months Ended March 31,
	2019			2018
	(In thousands)
Loss on disposal of inventory	$	187		$	—
Loss on ARO liability settlements	1,918			—
Disputed charges and related costs, net of recoveries	(14		)	2,335
Other, net	28			1,370
Other expenses, net	$	2,119		$	3,705

Business Segment Information (Tables)

3 Months Ended

Mar. 31, 2019

Segment Reporting [Abstract]

Schedule of business segment information

Financial information for each area is presented below:



	Ghana			Equatorial Guinea		Mauritania/Senegal			U.S. Gulf of Mexico			Corporate & Other			Eliminations			Total
	(in thousands)
Three months ended March 31, 2019
Revenues and other income:
Oil and gas revenue	$	122,919		$	88,805	$	—		$	85,066		$	—		$	—		$	296,790
Other income, net	—			—		—			135			72,809			(72,944		)	—
Total revenues and other income	122,919			88,805		—			85,201			72,809			(72,944		)	296,790
Costs and expenses:
Oil and gas production	30,057			22,605		—			27,137			—			—			79,799
Facilities insurance modifications, net	(20,021		)	—		—			—			—			—			(20,021		)
Exploration expenses	52			3,171		6,442			11,194			9,485			—			30,344
General and administrative	5,956			2,045		2,287			7,393			44,205			(25,978		)	35,908
Depletion, depreciation and amortization	54,863			23,017		15			39,090			1,110			—			118,095
Interest and other financing costs, net(1)	20,653			—		(6,793		)	5,929			17,036			(1,784		)	35,041
Derivatives, net	—			—		—			31,903			45,182			—			77,085
Other expenses, net	45,100			340		229			1,592			40			(45,182		)	2,119
Total costs and expenses	136,660			51,178		2,180			124,238			117,058			(72,944		)	358,370
Income (loss) before income taxes	(13,741		)	37,627		(2,180		)	(39,037		)	(44,249		)	—			(61,580		)
Income tax expense (benefit)	(4,983		)	15,531		—			(8,206		)	(11,016		)	—			(8,674		)
Net income (loss)	$	(8,758	)	$	22,096	$	(2,180	)	$	(30,831	)	$	(33,233	)	$	—		$	(52,906	)

Consolidated capital expenditures	$	34,967		$	14,936	$	2,252		$	45,882		$	12,191		$	—		$	110,228

As of March 31, 2019
Property and equipment, net	$	1,681,317		$	470,974	$	414,035		$	1,309,412		$	39,065		$	—		$	3,914,803
Total assets	$	1,938,645		$	533,244	$	528,068		$	3,369,271		$	10,092,342		$	(11,959,714	)	$	4,501,856

______________________________________


(1)	Interest expense is recorded based on actual third-party and intercompany debt agreements. Capitalized interest is recorded on the business unit where the assets reside.



	Ghana			Equatorial Guinea(1)			Mauritania/Senegal			U.S. Gulf of Mexico(2)		Corporate & Other			Eliminations(3)			Total
	(in thousands)
Three months ended March 31, 2018
Revenues and other income:
Oil and gas revenue	$	127,196		$	123,177		$	—		$	—	$	—		$	(123,177	)	$	127,196
Other income, net	(18		)	143			—			—		65,060			(65,204		)	(19		)
Total revenues and other income	127,178			123,320			—			—		65,060			(188,381		)	127,177
Costs and expenses:
Oil and gas production	46,768			25,850			—			—		—			(25,850		)	46,768
Facilities insurance modifications, net	8,449			—			—			—		—			—			8,449
Exploration expenses	224			869			3,198			—		16,902			—			21,193
General and administrative	5,253			985			1,291			—		39,111			(24,757		)	21,883
Depletion, depreciation and amortization	53,351			53,998			15			—		911			(53,998		)	54,277
Interest and other financing costs, net(4)	21,254			(1		)	(3,921		)	—		10,146			(1,784		)	25,694
Derivatives, net	—			—			—			—		38,478			—			38,478
(Gain) loss on equity method investments, net	—			—			—			—		—			(18,696		)	(18,696		)
Other expenses, net	40,809			121			1			—		1,254			(38,480		)	3,705
Total costs and expenses	176,108			81,822			584			—		106,802			(163,565		)	201,751
Income (loss) before income taxes	(48,930		)	41,498			(584		)	—		(41,742		)	(24,816		)	(74,574		)
Income tax expense (benefit)	(24,408		)	24,816			—			—		60			(24,816		)	(24,348		)
Net income (loss)	$	(24,522	)	$	16,682		$	(584	)	$	—	$	(41,802	)	$	—		$	(50,226	)

Consolidated capital expenditures	$	18,102		$	6,891		$	3,256		$	—	$	29,380		$	—		$	57,629

As of March 31, 2018
Property and equipment, net	$	1,868,283		$	7,931		$	385,386		$	—	$	44,937		$	—		$	2,306,537
Total assets	$	2,165,726		$	214,546		$	499,082		$	—	$	8,516,046		$	(8,364,872	)	$	3,030,528

______________________________________


(1)	Includes our proportionate share of our equity method investment in KTIPI, including our basis difference which is reflected in depletion, depreciation and amortization for the three months ended March 31, 2018, except for capital expenditures. See Note 7 - Equity Method Investments for additional information regarding our equity method investments.


(2)	No activity prior to September 14, 2018, the DGE acquisition date.


(3)	Includes elimination of proportionate consolidation amounts recorded for KTIPI to reconcile to (Gain) loss on equity method investments, net as reported in the consolidated statements of operations.


(4)	Interest expense is recorded based on actual third-party and intercompany debt agreements. Capitalized interest is recorded on the business unit where the assets reside.



	Three Months Ended March 31,
	2019			2018
	(In thousands)
Consolidated capital expenditures:
Consolidated Statements of Cash Flows - Investing activities:
Oil and gas assets	$	78,377		$	34,712
Other property	1,071			1,757
Adjustments:
Changes in capital accruals	14,925			4,684
Exploration expense, excluding unsuccessful well costs(1)	30,504			21,150
Capitalized interest	(7,251		)	(4,820		)
Other	(7,398		)	146
Total consolidated capital expenditures	$	110,228		$	57,629

______________________________________


(1)	Unsuccessful well costs are included in oil and gas assets when incurred.

Accounting Policies (Details) - USD ($) $ in Thousands	3 Months Ended
Accounting Policies (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017
Cash, Cash Equivalents and Restricted Cash
Cash and cash equivalents	$ 134,423		$ 173,515
Restricted cash - current	537		4,527
Restricted cash - long-term	7,574		7,574
Total cash, cash equivalents and restricted cash shown in the consolidated statement of cash flows	142,534		185,616	$ 255,728	$ 304,986
Inventories
Materials and supplies inventory	78,100		83,400
Hydrocarbons inventory	9,200		$ 1,400
Leases
Other assets (right-of-use assets)	22,410
Total lease liabilities	$ 23,726
Accounting Standards Update 2016-02
Leases
Other assets (right-of-use assets)		$ 21,700
Total lease liabilities		$ 21,700
Sales Revenue, Net \| Customer Concentration Risk
Risks and Uncertainties
Concentration risk, percentage	22.00%

Accounting Policies Summary of Oil and Gas Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Disaggregation of Revenue [Line Items]
Provisional oil sales contracts	$ (73,807)	$ (38,966)
Oil and gas revenue	296,790	127,196
Oil and gas revenue
Disaggregation of Revenue [Line Items]
Provisional oil sales contracts	3,278	(841)
Oil and gas revenue	296,790	127,196
Equatorial Guinea
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	89,115	0
Ghana
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	119,330	128,037
Gulf of Mexico
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 85,067	$ 0

Acquisitions and Divestitures (Details) $ in Millions	1 Months Ended						3 Months Ended
Acquisitions and Divestitures (Details) $ in Millions	Mar. 31, 2019 km²	Oct. 31, 2018 company	Sep. 30, 2018 USD ($)	Aug. 31, 2018 USD ($) km² sub_period block	Jun. 30, 2018 km²	Mar. 31, 2018 km² block	Mar. 31, 2019 USD ($) km² sub_period block
Acquisitions and Divestitures
Number of companies in alliance \| company		2
Deep Gulf Energy, LP
Acquisitions and Divestitures
Total purchase price \| $			$ 1,275.0
Cash consideration \| $			952.6
Transaction related costs \| $			14.9
U.S. Gulf Of Mexico Lease Sale 452 Blocks
Acquisitions and Divestitures
Number of blocks \| block							9
Petroleum Agreement \| Marine XXI Block
Acquisitions and Divestitures
Participating interests							85.00%
Area of petroleum exploration	2,350						2,350
Exploration period							4 years
3D seismic requirements							2,200
Number of sub-periods \| sub_period							2
First sub exploration period							3 years
Petroleum Agreement \| Blocks 10 and 13
Acquisitions and Divestitures
Participating interests						35.00%
Area of petroleum exploration						13,600
Exploration period						4 years
3D seismic requirements						13,500
First sub exploration period						4 years
Number of blocks \| block						2
Petroleum Agreement \| Blocks EG-21, S and W
Acquisitions and Divestitures
Area of petroleum exploration				6,000
Exploration period				5 years
3D seismic requirements				6,000
Number of sub-periods \| sub_period				2
First sub exploration period				3 years
Number of blocks \| block				3
Second sub exploration period				2 years
Farm-in agreement \| U.S. Gulf Of Mexico Garden Banks Blocks
Acquisitions and Divestitures
Number of blocks \| block							18
Farm-in agreement \| U.S. Gulf Of Mexico Blocks
Acquisitions and Divestitures
Number of blocks \| block							3
Farm-in agreement \| Block EG-24
Acquisitions and Divestitures
Area of petroleum exploration	3,500						3,500
Exploration period					3 years
3D seismic requirements					3,000
First sub exploration period					4 years
Participation interest acquired	80.00%				40.00%
Farm out agreement \| Blocks EG-21, S and W
Acquisitions and Divestitures
Participating interests				40.00%
Gain on sale of assets \| $				$ 7.7			$ 7.7
SPNC \| Petroleum Agreement \| Marine XXI Block
Acquisitions and Divestitures
Carried participating interest percentage	15.00%						15.00%
Participating interest to be assigned, at least	15.00%						15.00%
BP \| Petroleum Agreement \| Blocks 10 and 13
Acquisitions and Divestitures
Participating interests						50.00%
ANP STP \| Petroleum Agreement \| Blocks 10 and 13
Acquisitions and Divestitures
Carried participating interest percentage						15.00%
Trident \| Farm out agreement \| Blocks EG-21, S and W
Acquisitions and Divestitures
Participation interest acquired				40.00%
GEPetrol \| Petroleum Agreement \| Blocks EG-21, S and W
Acquisitions and Divestitures
Carried participating interest percentage				20.00%
Percentage converted from carried to participating				20.00%
GEPetrol \| Farm-in agreement \| Block EG-24
Acquisitions and Divestitures
Carried participating interest percentage					20.00%
Percentage converted from carried to participating					20.00%
Common Shares \| Deep Gulf Energy, LP
Acquisitions and Divestitures
Equity consideration \| $			$ 307.9

Joint Interest Billings and Related Party Receivables (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2014	Mar. 31, 2019	Dec. 31, 2018
Joint interest billings
Joint interest billings, net		$ 54,580	$ 64,572
Long-term receivables - joint interest billings		20,670	19,002
Related party receivable		11	5,580
TEN Discoveries \| GNPC
Joint interest billings
Joint interest billings, net		14,000	14,000
Long-term receivables - joint interest billings		$ 15,200	14,000
TEN Discoveries \| GNPC
Joint interest billings
GNPC's paying interest	5.00%
Kosmos-Trident International Petroleum Inc.
Joint interest billings
Related party receivable			$ 5,600
Kosmos-Trident International Petroleum Inc. \| Trident
Joint interest billings
Ownership percentage			50.00%

Property and Equipment (Details) - USD ($) $ in Thousands	3 Months Ended
Property and Equipment (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Oil and gas properties:
Proved properties	$ 3,177,330		$ 2,773,276
Unproved properties	857,009		759,472
Support equipment and facilities	1,528,308		1,463,213
Total oil and gas properties	5,562,647		4,995,961
Accumulated depletion	(1,662,063)		(1,551,097)
Oil and gas properties, net	3,900,584		3,444,864
Other property	52,815		51,987
Accumulated depreciation	(38,596)		(37,150)
Other property, net	14,219		14,837
Property and equipment, net	3,914,803	$ 2,306,537	$ 3,459,701
Depletion expense	$ 111,000	$ 51,600

Suspended Well Costs - Summary of Suspended Well Costs (Details)	3 Months Ended
	Mar. 31, 2019 USD ($)	Mar. 31, 2019 USD ($) project	Dec. 31, 2018 USD ($) project
Oil and Gas Exploration and Production Industries Disclosures [Abstract]
Capitalized exploratory well costs subsequently expensed in the same period	$ 0
Reconciliation of capitalized exploratory well costs on completed wells
Beginning balance	367,665,000
Additions to capitalized exploratory well costs pending the determination of proved reserves	2,410,000
Reclassification due to determination of proved reserves	0
Capitalized exploratory well costs charged to expense	0
Ending balance	370,075,000
Aging of capitalized exploratory well costs and number of projects for which exploratory well costs were capitalized for more than one year
Exploratory well costs capitalized for a period of one year or less		$ 0	$ 0
Exploratory well costs capitalized for a period of one to two years		127,532,000	299,253,000
Exploratory well costs capitalized for a period of three years		242,543,000	68,412,000
Ending balance	$ 367,665,000	$ 370,075,000	$ 367,665,000
Number of projects that have exploratory well costs that have been capitalized for a period greater than one year \| project		3	3

Equity Method Investments - Narrative (Details) - Kosmos-Trident International Petroleum Inc.	Jan. 01, 2019	Dec. 31, 2018
Schedule of Equity Method Investments [Line Items]
Ownership percentage		50.00%
Ceiba Field And Okume Complex
Schedule of Equity Method Investments [Line Items]
Direct interest acquired due to transfer	40.375%

Equity Method Investments - Summary of Financial Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Costs and expenses:
Equity in earnings - KTIPI	$ 0	$ 18,696
Kosmos-Trident International Petroleum Inc.
Schedule of Equity Method Investments [Line Items]
Basis presented			100.00%
Assets
Total current assets			$ 149,950
Property and equipment, net			271,627
Other assets			21
Total assets			421,598
Liabilities and stockholders' equity
Total current liabilities			226,311
Total long-term liabilities			536,178
Shareholders' equity:
Total shareholders' equity			(340,891)
Total liabilities and shareholders' equity			$ 421,598
Revenues and other income:
Oil and gas revenue		246,354
Other income		287
Total revenues and other income		246,641
Costs and expenses:
Oil and gas production		51,700
Depletion, depreciation and amortization		54,070
Other expenses, net		(79)
Total costs and expenses		105,691
Income before income taxes		140,950
Income tax expense		49,632
Net income		91,318
Kosmos' share of net income		45,659
Basis difference amortization		26,963
Equity in earnings - KTIPI		$ 18,696

Equity Method Investments - Asset Acquisition (Details) - USD ($) $ in Thousands		3 Months Ended
	Jan. 01, 2019	Mar. 31, 2019	Dec. 31, 2018
Liabilities assumed:
Asset retirement obligations		$ 3,348
Carrying value:
Equity method investment carrying value at December 31, 2018		$ 0	$ 51,896
Ceiba Field And Okume Complex Acquisition
Assets acquired:
Proved oil and gas properties	$ 372,144
Unproved oil and gas properties	103,909
Prepaids and other	7,273
Total assets acquired	483,326
Liabilities assumed:
Asset retirement obligations	114,395
Deferred tax liabilities	247,636
Accrued liabilities and other	69,399
Total liabilities assumed	$ 431,430

Debt - Schedule of Instruments (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Debt
Outstanding debt principal	$ 2,250,000	$ 2,175,000
Unamortized issuance costs and discount	(54,174)	(54,453)
Long-term debt, net	2,195,826	2,120,547
Senior Secured Notes
Debt
Outstanding debt principal	525,000	525,000
Unamortized issuance costs and discount	(12,000)	(14,000)
The Facility \| Revolving Credit Facility
Debt
Outstanding debt principal	1,500,000	1,325,000
Unamortized issuance costs and discount	(42,200)	(40,500)
Corporate Revolver \| Revolving Credit Facility
Debt
Outstanding debt principal	$ 225,000	$ 325,000

Debt - Facility (Details)	1 Months Ended	3 Months Ended
Debt - Facility (Details)	Feb. 28, 2018 USD ($)	Mar. 31, 2019 USD ($)	Mar. 31, 2018 USD ($)	Apr. 30, 2019 USD ($)	Aug. 31, 2018 USD ($) financial_institution
Debt Instrument [Line Items]
Loss on extinguishment of debt		$ 0	$ 4,056,000
The Facility \| Revolving Credit Facility
Debt Instrument [Line Items]
Total commitment	$ 1,500,000,000	1,700,000,000.0
Additional commitments	500,000,000.0				$ 200,000,000
Number of financial institutions \| financial_institution					2
Loss on extinguishment of debt	$ 4,100,000
Net deferred financing costs		42,200,000
Amount outstanding		1,500,000,000
Undrawn availability		200,000,000
Availability period of revolving-credit	1 month
Amount outstanding under letters of credit		$ 0
Subsequent Event \| The Facility \| Revolving Credit Facility
Debt Instrument [Line Items]
Undrawn availability				$ 100,000,000

Debt - Corporate Revolver (Details) - USD ($)	1 Months Ended
Debt - Corporate Revolver (Details) - USD ($)	Aug. 31, 2018	Mar. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Net deferred financing costs		$ 8,283,000	$ 8,937,000
Corporate Revolver \| Revolving Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 400,000,000
Change in basis points	(1.00%)
Applicable margin	5.00%
Commitment fee percentage	30.00%
Amount outstanding		225,000,000
Undrawn availability		175,000,000
Net deferred financing costs		$ 8,300,000

Debt - Revolving Letter of Credit Facility (Details) - Revolving Letter of Credit Facility	Mar. 31, 2019 USD ($) letter_of_credit	Dec. 31, 2018 USD ($)
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 20,000,000
Number of letters of credit \| letter_of_credit	6
Amount outstanding	$ 9,400,000

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References + Details

Debt - 7.875% Senior Secured Notes due 2021 (Details) - USD ($)	1 Months Ended			3 Months Ended
	Apr. 30, 2019	Apr. 30, 2015	Aug. 31, 2014	Mar. 31, 2019	Mar. 31, 2018
Debt Instrument [Line Items]
Gain (loss) on extinguishment of debt				$ 0	$ (4,056,000)
Senior Secured Notes \| 7.875% senior notes due 2021
Debt Instrument [Line Items]
Interest rate			7.875%
Senior notes offering face amount		$ 225,000,000	$ 300,000,000
Proceeds, net of offering discounts and deferred financing costs		$ 206,800,000	$ 292,500,000
Subsequent Event \| Senior Secured Notes \| 7.875% senior notes due 2021
Debt Instrument [Line Items]
Debt redeemed	$ 543,800,000
Gain (loss) on extinguishment of debt	$ (22,900,000)

Debt - 7.125% Senior Notes due 2026 (Details) - Senior Notes - USD ($)	1 Months Ended			3 Months Ended
	Apr. 30, 2019	Apr. 30, 2015	Aug. 31, 2014	Mar. 31, 2019
7.125% Senior Notes due 2026
Debt Instrument [Line Items]
Redemption price percentage following change of control				101.00%
Redemption price percentage following sell of certain assets				100.00%
7.875% senior notes due 2021
Debt Instrument [Line Items]
Senior notes offering face amount		$ 225,000,000	$ 300,000,000
Interest rate			7.875%
Net proceeds from debt		$ 206,800,000	$ 292,500,000
Subsequent Event \| 7.125% Senior Notes due 2026
Debt Instrument [Line Items]
Senior notes offering face amount	$ 650,000,000
Interest rate	7.125%
Net proceeds from debt	$ 640,000,000
Any time prior to April 4, 2022 \| 7.125% Senior Notes due 2026
Debt Instrument [Line Items]
Percentage of principal balance available to be redeemed				40.00%
Redemption price, as percent of the principal amount				107.10%
Any time prior to April 4, 2022 with make-whole premium \| 7.125% Senior Notes due 2026
Debt Instrument [Line Items]
Redemption price, as percent of the principal amount				100.00%
On or after April 4, 2022, but before April 4, 2023 \| 7.125% Senior Notes due 2026
Debt Instrument [Line Items]
Redemption price, as percent of the principal amount				103.60%
On or after April 4, 2023, but before April 4, 2024 \| 7.125% Senior Notes due 2026
Debt Instrument [Line Items]
Redemption price, as percent of the principal amount				101.80%
On or after April 4, 2024 and thereafter \| 7.125% Senior Notes due 2026
Debt Instrument [Line Items]
Redemption price, as percent of the principal amount				100.00%

Debt - Maturities (Details) - USD ($)	Apr. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Apr. 30, 2015	Aug. 31, 2014
Scheduled maturities of debt during the five year period and thereafter
Total		$ 2,250,000,000	$ 2,175,000,000
2019		0
2020		0
2021		799,800,000
2022		509,200,000
2023		271,600,000
Thereafter		669,400,000
Senior Notes
Scheduled maturities of debt during the five year period and thereafter
Total		525,000,000	$ 525,000,000
Senior Notes \| 7.875% senior notes due 2021
Scheduled maturities of debt during the five year period and thereafter
Total		$ 525,000,000
Interest rate					7.875%
Senior notes offering face amount				$ 225,000,000	$ 300,000,000
Subsequent Event \| Senior Notes \| 7.125% Senior Notes due 2026
Scheduled maturities of debt during the five year period and thereafter
Interest rate	7.125%
Senior notes offering face amount	$ 650,000,000

Debt - Interest and other financing costs, net (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Debt Disclosure [Abstract]
Interest expense	$ 38,172	$ 24,893
Amortization—deferred financing costs	2,387	2,440
Loss on extinguishment of debt	0	4,056
Capitalized interest	(7,251)	(4,820)
Deferred interest	836	(1,256)
Interest income	(652)	(948)
Other, net	1,549	1,329
Interest and other financing costs, net	$ 35,041	$ 25,694

Derivative Financial Instruments - Schedule of oil derivative contracts (Details)	1 Months Ended	3 Months Ended
	Apr. 30, 2019 $ / bbl MBbls	Mar. 31, 2019 $ / bbl MBbls
Dated Brent \| Term April 2019 To December 2019 \| Three-way collars
Derivative Financial Instruments
Volume (mbbls) \| MBbls		7,880
Weighted Average Price Per Bbl [Abstract]
Net Deferred Premium Payable/ (Receivable) (usd per bbl)		1.17
Swap (usd per bbl)		0.00
Sold Put (usd per bbl)		43.81
Floor (usd per bbl)		53.33
Ceiling (usd per bbl)		73.57
Dated Brent \| Term April 2019 To December 2019 \| Sold calls
Derivative Financial Instruments
Volume (mbbls) \| MBbls		688
Weighted Average Price Per Bbl [Abstract]
Net Deferred Premium Payable/ (Receivable) (usd per bbl)		0.00
Swap (usd per bbl)		0.00
Sold Put (usd per bbl)		0.00
Floor (usd per bbl)		0.00
Ceiling (usd per bbl)		80.00
Dated Brent \| Term January 2020 To December 2020 \| Three-way collars
Derivative Financial Instruments
Volume (mbbls) \| MBbls		4,500
Weighted Average Price Per Bbl [Abstract]
Net Deferred Premium Payable/ (Receivable) (usd per bbl)		0.58
Swap (usd per bbl)		0.00
Sold Put (usd per bbl)		45.00
Floor (usd per bbl)		57.50
Ceiling (usd per bbl)		81.91
Dated Brent \| Term January 2020 To December 2020 \| Sold calls
Derivative Financial Instruments
Volume (mbbls) \| MBbls		8,000
Weighted Average Price Per Bbl [Abstract]
Net Deferred Premium Payable/ (Receivable) (usd per bbl)		1.17
Swap (usd per bbl)		0.00
Sold Put (usd per bbl)		0.00
Floor (usd per bbl)		0.00
Ceiling (usd per bbl)		85.00
NYMEX WTI \| Term April 2019 To December 2019 \| Swaps
Derivative Financial Instruments
Volume (mbbls) \| MBbls		1,224
Weighted Average Price Per Bbl [Abstract]
Net Deferred Premium Payable/ (Receivable) (usd per bbl)		0.00
Swap (usd per bbl)		52.22
Sold Put (usd per bbl)		0.00
Floor (usd per bbl)		0.00
Ceiling (usd per bbl)		0.00
NYMEX WTI \| Term April 2019 To June 2019 \| Collars
Derivative Financial Instruments
Volume (mbbls) \| MBbls		169
Weighted Average Price Per Bbl [Abstract]
Net Deferred Premium Payable/ (Receivable) (usd per bbl)		0.00
Swap (usd per bbl)		0.00
Sold Put (usd per bbl)		0.00
Floor (usd per bbl)		57.77
Ceiling (usd per bbl)		63.70
Argus LLS \| Term April 2019 To December 2019 \| Collars
Derivative Financial Instruments
Volume (mbbls) \| MBbls		750
Weighted Average Price Per Bbl [Abstract]
Net Deferred Premium Payable/ (Receivable) (usd per bbl)		0.00
Swap (usd per bbl)		0.00
Sold Put (usd per bbl)		0.00
Floor (usd per bbl)		60.00
Ceiling (usd per bbl)		88.75
Subsequent Event \| Dated Brent \| Term January 2020 To December 2020 \| Three-way collars
Derivative Financial Instruments
Volume (mbbls) \| MBbls	1,500
Weighted Average Price Per Bbl [Abstract]
Sold Put (usd per bbl)	45.00
Floor (usd per bbl)	57.50
Ceiling (usd per bbl)	75.00

Derivative Financial Instruments - Derivatives instrument and gain/loss from derivatives (Details) - USD ($)	Mar. 31, 2019	Dec. 31, 2018
Derivative instruments, Balance Sheet Location
Derivatives assets—current	$ 17,289,000	$ 38,785,000
Derivatives assets—long-term	8,243,000	14,312,000
Derivatives liabilities—current	(51,713,000)	(12,172,000)
Derivatives liabilities—long-term	(13,306,000)	(10,181,000)
Derivatives not designated as hedging instruments:
Derivative instruments, Balance Sheet Location
Total derivatives not designated as hedging instruments	(39,487,000)	30,744,000
Derivatives not designated as hedging instruments: \| Commodity
Derivative instruments, Balance Sheet Location
Derivatives assets—current	17,289,000	38,785,000
Derivatives assets—long-term	8,243,000	14,312,000
Derivatives liabilities—current	(51,713,000)	(12,172,000)
Derivatives liabilities—long-term	(13,306,000)	(10,181,000)
Net deferred premiums payable related to commodity derivative contracts - current assets	5,500,000	1,600,000
Net deferred premiums payable related to commodity derivative contracts - non-current assets	100,000	1,300,000
Net deferred premiums payable related to commodity derivative contracts - current liabilities	11,000,000	18,000,000
Net deferred premiums payable related to commodity derivative contracts - non-current liabilities	2,000,000	500,000
Oil and gas revenue \| Derivatives not designated as hedging instruments: \| Commodity
Derivative instruments, Balance Sheet Location
Derivatives assets—current	$ 0	$ 400,000

Derivative Financial Instruments - Schedule of derivative instruments by location of gain/(loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Derivative instruments, Location of Gain/(Loss)
Amount of Gain/(Loss)	$ (73,807)	$ (38,966)
Commodity \| Oil and gas revenue
Derivative instruments, Location of Gain/(Loss)
Amount of Gain/(Loss)	3,278	(841)
Commodity \| Derivatives, net
Derivative instruments, Location of Gain/(Loss)
Amount of Gain/(Loss)	(77,085)	(38,478)
Interest rate \| Interest expense
Derivative instruments, Location of Gain/(Loss)
Amount of Gain/(Loss)	$ 0	$ 353

Fair Value Measurements (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Carrying Value
Liabilities:
Long-term debt	$ 2,238,006	$ 2,161,873
Fair Value
Liabilities:
Long-term debt	2,260,337	2,175,026
Senior Notes \| Carrying Value
Liabilities:
Long-term debt	513,006	511,873
Senior Notes \| Fair Value
Liabilities:
Long-term debt	535,337	525,026
Recurring basis
Liabilities:
Total fair value, net	(39,487)	30,744
Recurring basis \| Commodity
Assets:
Derivative asset, fair value	25,532	53,097
Liabilities:
Derivative liability, fair value	(65,019)	(22,353)
Recurring basis \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Liabilities:
Total fair value, net	0	0
Recurring basis \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Commodity
Assets:
Derivative asset, fair value	0	0
Liabilities:
Derivative liability, fair value	0	0
Recurring basis \| Significant Other Observable Inputs (Level 2)
Liabilities:
Total fair value, net	(39,487)	30,744
Recurring basis \| Significant Other Observable Inputs (Level 2) \| Commodity
Assets:
Derivative asset, fair value	25,532	53,097
Liabilities:
Derivative liability, fair value	(65,019)	(22,353)
Recurring basis \| Significant Unobservable Inputs (Level 3)
Liabilities:
Total fair value, net	0	0
Recurring basis \| Significant Unobservable Inputs (Level 3) \| Commodity
Assets:
Derivative asset, fair value	0	0
Liabilities:
Derivative liability, fair value	0	0
Corporate Revolver \| Facility \| Carrying Value
Liabilities:
Long-term debt	225,000	325,000
Corporate Revolver \| Facility \| Fair Value
Liabilities:
Long-term debt	225,000	325,000
The Facility \| Facility \| Carrying Value
Liabilities:
Long-term debt	1,500,000	1,325,000
The Facility \| Facility \| Fair Value
Liabilities:
Long-term debt	$ 1,500,000	$ 1,325,000

Equity-based Compensation - Additional Information (Details) - LTIP - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense recognized		$ 8.4	$ 8.0
Tax benefit		1.3	0.9
Net tax shortfall (windfall) related to equity-based compensation		1.2	0.2
Fair value of awards vested		$ 13.2	$ 56.6
Vesting period		3 years
Number of additional shares authorized (in shares)	11,000,000.0
Number of shares authorized (in shares)		50,500,000.0
Number of shares remaining available for grant (in shares)		10,200,000
Market/Service Vesting Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant date fair value of awards granted (in dollars per share)		$ 6.02
Market/Service Vesting Restricted Stock Units \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage of the awards granted (up to)		0.00%
Grant date fair value of awards granted (in dollars per share)		$ 4.83
Expected volatility		44.00%
Risk-free interest rate		0.80%
Market/Service Vesting Restricted Stock Units \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage of the awards granted (up to)		200.00%
Grant date fair value of awards granted (in dollars per share)		$ 12.96
Expected volatility		52.00%
Risk-free interest rate		2.50%
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense not yet recognized		$ 54.9
Weighted average period over which compensation expense is to be recognized		2 years 4 months 6 days

Equity-based Compensation - Schedule of awards (Details) - LTIP shares in Thousands	3 Months Ended
	Mar. 31, 2019 $ / shares shares
Service Vesting Restricted Stock Units
Outstanding unvested awards activity
Outstanding at the beginning of the period (in shares) \| shares	4,115
Granted (in shares) \| shares	2,726
Forfeited (in shares) \| shares	(53)
Vested (in shares) \| shares	(1,797)
Outstanding at the end of the period (in shares) \| shares	4,991
Weighted-Average Grant-Date Fair Value
Outstanding at beginning of the period (in dollars per share)	$ 6.42
Granted (in dollars per share)	4.81
Forfeited (in dollars per share)	6.46
Vested (in dollars per share)	5.78
Outstanding at the end of the period (in dollars per share)	$ 5.76
Market/Service Vesting Restricted Stock Units
Outstanding unvested awards activity
Outstanding at the beginning of the period (in shares) \| shares	6,716
Granted (in shares) \| shares	3,041
Forfeited (in shares) \| shares	(275)
Vested (in shares) \| shares	(1,269)
Outstanding at the end of the period (in shares) \| shares	8,213
Weighted-Average Grant-Date Fair Value
Outstanding at beginning of the period (in dollars per share)	$ 9.02
Granted (in dollars per share)	6.02
Forfeited (in dollars per share)	10.64
Vested (in dollars per share)	6.36
Outstanding at the end of the period (in dollars per share)	8.41
Minimum \| Market/Service Vesting Restricted Stock Units
Weighted-Average Grant-Date Fair Value
Granted (in dollars per share)	$ 4.83
Vesting percentage of the awards granted	0.00%
Maximum \| Market/Service Vesting Restricted Stock Units
Weighted-Average Grant-Date Fair Value
Granted (in dollars per share)	$ 12.96
Vesting percentage of the awards granted	200.00%

Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended
Income Taxes (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Mar. 31, 2018
Income Taxes
Effective tax rate (as a percent)	14.00%	33.00%
Income (loss) before income taxes	$ (61,580)	$ (74,574)
Uncertain tax positions	0
United States
Income Taxes
Income (loss) before income taxes	(55,741)	1,633
Bermuda
Income Taxes
Income (loss) before income taxes	$ 0	(16,071)
Foreign—other
Income Taxes
Effective tax rate (as a percent)	0.00%
Statutory tax rate (as a percent)	0.00%
Income (loss) before income taxes	$ (5,839)	$ (60,136)

Net Loss Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Numerator:
Net loss allocable to common stockholders	$ (52,906)	$ (50,226)
Weighted average number of shares outstanding:
Basic (in shares)	401,164	395,600
Restricted stock units (in shares)	0	0
Diluted (in shares)	401,164	395,600
Net loss per share:
Basic (in dollars per share)	$ (0.13)	$ (0.13)
Diluted (in dollars per share)	$ (0.13)	$ (0.13)
Outstanding restricted stock awards and units excluded from the computations of diluted net income per share (in shares)	8,900	11,300

Commitments and Contingencies (Details)				1 Months Ended	3 Months Ended
Commitments and Contingencies (Details)	May 03, 2019 $ / shares	Mar. 28, 2019 USD ($)	Feb. 25, 2019 $ / shares	Feb. 28, 2019 USD ($) agreement	Mar. 31, 2019 USD ($) km² exploration_well $ / shares	Mar. 31, 2018 $ / shares	Dec. 31, 2018 USD ($)
Commitments and contingencies
Dividends declared per common stock (in dollars per share) \| $ / shares			$ 0.0452		$ 0.0452	$ 0
Dividends paid		$ 18,100,000
Mauritania
Commitments and contingencies
Number of exploration wells \| exploration_well					1
Namibia
Commitments and contingencies
Number of exploration wells \| exploration_well					1
Senegal
Commitments and contingencies
Number of exploration wells \| exploration_well					2
Sao Tome and Principe
Commitments and contingencies
Number of exploration wells \| exploration_well					1
3D seismic requirements \| km²					13,500
Surety Bond \| Gulf of Mexico
Commitments and contingencies
Cash collateral					$ 0		$ 600,000
Bureau Of Ocean Energy Management \| Surety Bond \| Gulf of Mexico
Commitments and contingencies
Required performance bonds					199,800,000		200,900,000
Third Party \| Surety Bond \| Gulf of Mexico
Commitments and contingencies
Required performance bonds					$ 3,700,000		$ 3,700,000
Carry Advance Agreements \| National Oil Companies Of Mauritania And Senegal
Commitments and contingencies
Number of agreements \| agreement				2
Share of development costs to be financed, up to				$ 239,700,000
Subsequent Event
Commitments and contingencies
Dividends declared per common stock (in dollars per share) \| $ / shares	$ 0.0452

Commitments and Contingencies - Leases (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($)
Lease, Cost [Abstract]
Operating lease cost	$ 1,407
Short-term lease cost	5
Total lease cost	1,412
Balance sheet classifications
Other assets (right-of-use assets)	22,410
Accrued liabilities (current maturities of leases)	2,842
Other long-term liabilities (non-current maturities of leases)	$ 20,884
Weighted average remaining lease term	9 years 1 month
Weighted average discount rate	9.90%
Operating cash flows for operating leases	$ 1,223
Operating Lease Liabilities, Payments Due [Abstract]
2019	2,078
2020	4,522
2021	3,852
2022	3,903
2023	3,916
Thereafter	19,549
Total undiscounted lease payments	37,820
Less: Imputed interest	(14,094)
Total lease liabilities	$ 23,726
Minimum
Lessee, Lease, Description [Line Items]
Operating lease, initial term	1 year
Maximum
Lessee, Lease, Description [Line Items]
Operating lease, initial term	10 years

Additional Financial Information (Details) - USD ($) $ in Thousands		3 Months Ended		12 Months Ended
	Jan. 01, 2019	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Accrued liabilities:
Exploration, development and production		$ 102,538		$ 92,613
Revenue payable		21,288		24,379
Current asset retirement obligations		5,776		6,617
Operating lease liabilities		2,842
General and administrative expenses		14,742		39,373
Interest		7,445		18,152
Income taxes		24,665		8,958
Taxes other than income		2,669		4,613
Derivatives		3,504		441
Other		2,472		450
Accrued liabilities		187,941		195,596
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Beginning asset retirement obligations		274,311		151,953
Additions associated with Equatorial Guinea - Ceiba Field and Okume Complex		114,395
Liabilities incurred during period		3,348
Liabilities settled during period		(2,232)
Revisions in estimated retirement obligations		1,164
Accretion expense		5,683
Ending asset retirement obligations	$ 151,953	151,953
Facilities insurance modifications, expenditures		11,000	$ 9,800
Facilities insurance modifications, insurance recoveries		31,000	1,300
Other Expenses, Net
Loss on disposal of inventory		187	0
Loss on ARO liability settlements		1,918	0
Disputed charges and related costs, net of recoveries		(14)	2,335
Other, net		28	1,370
Other expenses, net		$ 2,119	$ 3,705
Recoveries				$ 12,900
Kosmos-Trident International Petroleum Inc. \| Ceiba Field And Okume Complex
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Direct interest acquired due to transfer	40.375%

Business Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Segment Reporting Information [Line Items]
Oil and gas revenue	$ 296,790	$ 127,196
Other income, net	0	(19)
Total revenues and other income	296,790	127,177
Oil and gas production	79,799	46,768
Facilities insurance modifications, net	(20,021)	8,449
Exploration expenses	30,344	21,193
General and administrative	35,908	21,883
Depletion, depreciation and amortization	118,095	54,277
Interest and other financing costs, net	35,041	25,694
Derivatives, net	77,085	38,478
(Gain) loss on equity method investments, net	0	(18,696)
Other expenses, net	2,119	3,705
Total costs and expenses	358,370	201,751
Loss before income taxes	(61,580)	(74,574)
Income tax benefit	(8,674)	(24,348)
Net loss	(52,906)	(50,226)
Consolidated capital expenditures	110,228	57,629
Property and equipment, net	3,914,803	2,306,537	$ 3,459,701
Total assets	4,501,856	3,030,528	$ 4,088,189
Corporate & Other
Segment Reporting Information [Line Items]
Oil and gas revenue	0	0
Other income, net	72,809	65,060
Total revenues and other income	72,809	65,060
Oil and gas production	0	0
Facilities insurance modifications, net	0	0
Exploration expenses	9,485	16,902
General and administrative	44,205	39,111
Depletion, depreciation and amortization	1,110	911
Interest and other financing costs, net	17,036	10,146
Derivatives, net	45,182	38,478
(Gain) loss on equity method investments, net		0
Other expenses, net	40	1,254
Total costs and expenses	117,058	106,802
Loss before income taxes	(44,249)	(41,742)
Income tax benefit	(11,016)	60
Net loss	(33,233)	(41,802)
Consolidated capital expenditures	12,191	29,380
Property and equipment, net	39,065	44,937
Total assets	10,092,342	8,516,046
Eliminations
Segment Reporting Information [Line Items]
Oil and gas revenue	0	(123,177)
Other income, net	(72,944)	(65,204)
Total revenues and other income	(72,944)	(188,381)
Oil and gas production	0	(25,850)
Facilities insurance modifications, net	0	0
Exploration expenses	0	0
General and administrative	(25,978)	(24,757)
Depletion, depreciation and amortization	0	(53,998)
Interest and other financing costs, net	(1,784)	(1,784)
Derivatives, net	0	0
(Gain) loss on equity method investments, net		(18,696)
Other expenses, net	(45,182)	(38,480)
Total costs and expenses	(72,944)	(163,565)
Loss before income taxes	0	(24,816)
Income tax benefit	0	(24,816)
Net loss	0	0
Consolidated capital expenditures	0	0
Property and equipment, net	0	0
Total assets	(11,959,714)	(8,364,872)
Ghana \| Operating Segments
Segment Reporting Information [Line Items]
Oil and gas revenue	122,919	127,196
Other income, net	0	(18)
Total revenues and other income	122,919	127,178
Oil and gas production	30,057	46,768
Facilities insurance modifications, net	(20,021)	8,449
Exploration expenses	52	224
General and administrative	5,956	5,253
Depletion, depreciation and amortization	54,863	53,351
Interest and other financing costs, net	20,653	21,254
Derivatives, net	0	0
(Gain) loss on equity method investments, net		0
Other expenses, net	45,100	40,809
Total costs and expenses	136,660	176,108
Loss before income taxes	(13,741)	(48,930)
Income tax benefit	(4,983)	(24,408)
Net loss	(8,758)	(24,522)
Consolidated capital expenditures	34,967	18,102
Property and equipment, net	1,681,317	1,868,283
Total assets	1,938,645	2,165,726
Equatorial Guinea \| Operating Segments
Segment Reporting Information [Line Items]
Oil and gas revenue	88,805	123,177
Other income, net	0	143
Total revenues and other income	88,805	123,320
Oil and gas production	22,605	25,850
Facilities insurance modifications, net	0	0
Exploration expenses	3,171	869
General and administrative	2,045	985
Depletion, depreciation and amortization	23,017	53,998
Interest and other financing costs, net	0	(1)
Derivatives, net	0	0
(Gain) loss on equity method investments, net		0
Other expenses, net	340	121
Total costs and expenses	51,178	81,822
Loss before income taxes	37,627	41,498
Income tax benefit	15,531	24,816
Net loss	22,096	16,682
Consolidated capital expenditures	14,936	6,891
Property and equipment, net	470,974	7,931
Total assets	533,244	214,546
Mauritania And Senegal \| Operating Segments
Segment Reporting Information [Line Items]
Oil and gas revenue	0	0
Other income, net	0	0
Total revenues and other income	0	0
Oil and gas production	0	0
Facilities insurance modifications, net	0	0
Exploration expenses	6,442	3,198
General and administrative	2,287	1,291
Depletion, depreciation and amortization	15	15
Interest and other financing costs, net	(6,793)	(3,921)
Derivatives, net	0	0
(Gain) loss on equity method investments, net		0
Other expenses, net	229	1
Total costs and expenses	2,180	584
Loss before income taxes	(2,180)	(584)
Income tax benefit	0	0
Net loss	(2,180)	(584)
Consolidated capital expenditures	2,252	3,256
Property and equipment, net	414,035	385,386
Total assets	528,068	499,082
U.S. Gulf of Mexico \| Operating Segments
Segment Reporting Information [Line Items]
Oil and gas revenue	85,066	0
Other income, net	135	0
Total revenues and other income	85,201	0
Oil and gas production	27,137	0
Facilities insurance modifications, net	0	0
Exploration expenses	11,194	0
General and administrative	7,393	0
Depletion, depreciation and amortization	39,090	0
Interest and other financing costs, net	5,929	0
Derivatives, net	31,903	0
(Gain) loss on equity method investments, net		0
Other expenses, net	1,592	0
Total costs and expenses	124,238	0
Loss before income taxes	(39,037)	0
Income tax benefit	(8,206)	0
Net loss	(30,831)	0
Consolidated capital expenditures	45,882	0
Property and equipment, net	1,309,412	0
Total assets	$ 3,369,271	$ 0

Business Segment Information - Consolidated Capital Expenditures (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Segment Reporting [Abstract]
Oil and gas assets	$ 78,377	$ 34,712
Other property	1,071	1,757
Changes in capital accruals	14,925	4,684
Exploration expense, excluding unsuccessful well costs	30,504	21,150
Capitalized interest	(7,251)	(4,820)
Other	(7,398)	146
Consolidated capital expenditures	$ 110,228	$ 57,629

CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Statement of Cash Flows [Abstract]
Cash settlements on derivatives, net (commodity hedges)	$ (7.3)	$ (19.7)

Organization (Details)	3 Months Ended
Organization (Details)	Mar. 31, 2019 segment
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of reportable segments	4

Suspended Well Costs - Narrative (Details)	May 31, 2015 project
Greater Tortue Discovery
Capitalized Contract Cost [Line Items]
Number of additional appraisal wells drilled	2