Apache 10-Q 5 Nov 20 2020 Q3 Quarterly report Financial data

Cover

Cover - shares	9 Months Ended
	Sep. 30, 2020	Oct. 31, 2020
Entity Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2020
Document Transition Report	false
Entity File Number	1-4300
Entity Registrant Name	APACHE CORPORATION
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	41-0747868
Entity Address, Address Line One	One Post Oak Central, 2000 Post Oak Boulevard, Suite 100
Entity Address, City or Town	Houston
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	77056-4400
City Area Code	713
Local Phone Number	296-6000
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		377,478,182
Amendment Flag	false
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q3
Entity Central Index Key	0000006769
Current Fiscal Year End Date	--12-31
Nasdaq Global Select Market
Entity Information [Line Items]
Title of 12(b) Security	Common Stock, $0.625 par value
Trading Symbol	APA
Security Exchange Name	NASDAQ

STATEMENT OF CONSOLIDATED OPERA

STATEMENT OF CONSOLIDATED OPERATIONS (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
REVENUES AND OTHER:
Derivative instrument gains (losses), net	$ 16	$ (2)	$ (262)	$ (40)
Gain (loss) on divestitures, net	(1)	0	24	20
Other, net	9	34	41	33
Total revenues and other	1,144	1,500	3,019	4,775
OPERATING EXPENSES:
Lease operating expenses	259	350	858	1,104
Taxes other than income	34	44	90	141
Exploration	58	56	187	220
General and administrative	52	98	214	323
Transaction, reorganization, and separation	7	7	44	17
Depreciation, depletion, and amortization	398	711	1,382	1,959
Accretion expense	27	27	81	80
Impairments	0	9	4,492	249
Financing costs, net	99	95	168	365
Total operating expenses	1,072	1,486	7,929	4,748
NET INCOME (LOSS) BEFORE INCOME TAXES	72	14	(4,910)	27
Current income tax provision	58	141	120	514
Deferred income tax benefit	(27)	(10)	(71)	(52)
NET INCOME (LOSS) INCLUDING NONCONTROLLING INTERESTS	41	(117)	(4,959)	(435)
NET LOSS ATTRIBUTABLE TO COMMON STOCK	$ (4)	$ (170)	$ (4,870)	$ (577)
NET LOSS PER COMMON SHARE:
Basic (in USD per share)	$ (0.01)	$ (0.45)	$ (12.89)	$ (1.53)
Diluted (in USD per share)	$ (0.02)	$ (0.45)	$ (12.89)	$ (1.53)
WEIGHTED-AVERAGE NUMBER OF COMMON SHARES OUTSTANDING:
Basic (in shares)	378	377	378	377
Diluted (in shares)	378	377	378	377
Altus Preferred Unit limited partners
OPERATING EXPENSES:
Net income (loss) attributable to noncontrolling interest	$ 19	$ 18	$ 56	$ 22
Noncontrolling interests, Egypt
OPERATING EXPENSES:
Net income (loss) attributable to noncontrolling interest	24	38	(138)	125
Noncontrolling interests, Altus
OPERATING EXPENSES:
Net income (loss) attributable to noncontrolling interest	2	(3)	(7)	(5)
Oil and gas
REVENUES AND OTHER:
Oil and gas production revenues	1,120	1,468	3,216	4,762
Oil and gas, excluding purchased
REVENUES AND OTHER:
Oil and gas production revenues	1,046	1,438	2,979	4,690
OPERATING EXPENSES:
Cost of oil and gas purchased	63	66	206	230
Oil and gas, purchased
REVENUES AND OTHER:
Oil and gas production revenues	74	30	237	72
OPERATING EXPENSES:
Cost of oil and gas purchased	$ 75	$ 23	$ 207	$ 60

STATEMENT OF CONSOLIDATED COMPR

STATEMENT OF CONSOLIDATED COMPREHENSIVE INCOME (LOSS) (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
NET INCOME (LOSS) INCLUDING NONCONTROLLING INTERESTS	$ 41	$ (117)	$ (4,959)	$ (435)
OTHER COMPREHENSIVE INCOME (LOSS), NET OF TAX:
Share of equity method interests other comprehensive income (loss)	1	(1)	0	(1)
COMPREHENSIVE INCOME (LOSS) INCLUDING NONCONTROLLING INTERESTS	42	(118)	(4,959)	(436)
COMPREHENSIVE LOSS ATTRIBUTABLE TO COMMON STOCK	(3)	(171)	(4,870)	(578)
Altus Preferred Unit limited partners
OTHER COMPREHENSIVE INCOME (LOSS), NET OF TAX:
Comprehensive income attributable to noncontrolling interest	19	18	56	22
Noncontrolling interests, Egypt
OTHER COMPREHENSIVE INCOME (LOSS), NET OF TAX:
Comprehensive income attributable to noncontrolling interest	24	38	(138)	125
Noncontrolling interests, Altus
OTHER COMPREHENSIVE INCOME (LOSS), NET OF TAX:
Comprehensive income attributable to noncontrolling interest	$ 2	$ (3)	$ (7)	$ (5)

STATEMENT OF CONSOLIDATED CASH

STATEMENT OF CONSOLIDATED CASH FLOWS (Unaudited) - USD ($)	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss including noncontrolling interests	$ (4,959,000,000)	$ (435,000,000)
Adjustments to reconcile net loss to net cash provided by operating activities:
Unrealized derivative instrument losses, net	142,000,000	52,000,000
Gain on divestitures	(24,000,000)	(20,000,000)
Exploratory dry hole expense and unproved leasehold impairments	138,000,000	107,000,000
Depreciation, depletion, and amortization	1,382,000,000	1,959,000,000
Accretion expense	81,000,000	80,000,000
Impairments	4,492,000,000	249,000,000
Deferred income tax benefit	(71,000,000)	(52,000,000)
Loss (gain) on extinguishment of debt	(152,000,000)	75,000,000
Other	45,000,000	35,000,000
Changes in operating assets and liabilities:
Receivables	202,000,000	124,000,000
Inventories	16,000,000	(16,000,000)
Drilling advances	(10,000,000)	(2,000,000)
Deferred charges and other	(7,000,000)	(1,000,000)
Accounts payable	(211,000,000)	(82,000,000)
Accrued expenses	(211,000,000)	(1,000,000)
Deferred credits and noncurrent liabilities	37,000,000	17,000,000
NET CASH PROVIDED BY OPERATING ACTIVITIES	890,000,000	2,089,000,000
CASH FLOWS FROM INVESTING ACTIVITIES:
Additions to oil and gas property	(1,075,000,000)	(2,015,000,000)
Additions to Altus gathering, processing, and transmission facilities	(27,000,000)	(294,000,000)
Leasehold and property acquisitions	(3,000,000)	(39,000,000)
Contributions to Altus equity method interests	(286,000,000)	(338,000,000)
Acquisition of Altus equity method interests	0	(670,000,000)
Proceeds from sale of oil and gas properties	132,000,000	590,000,000
Other, net	(17,000,000)	(17,000,000)
NET CASH USED IN INVESTING ACTIVITIES	(1,276,000,000)	(2,783,000,000)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from Apache credit facility, net	87,000,000	0
Proceeds from Altus credit facility, net	184,000,000	235,000,000
Fixed-rate debt borrowings	1,238,000,000	989,000,000
Payments on fixed-rate debt	(980,000,000)	(1,150,000,000)
Distributions to noncontrolling interest - Egypt	(61,000,000)	(235,000,000)
Distributions to Altus Preferred Unit limited partners	(11,000,000)	0
Redeemable noncontrolling interest - Altus Preferred Unit limited partners	0	611,000,000
Dividends paid	(113,000,000)	(282,000,000)
Other	(43,000,000)	(25,000,000)
NET CASH PROVIDED BY FINANCING ACTIVITIES	301,000,000	143,000,000
NET DECREASE IN CASH AND CASH EQUIVALENTS	(85,000,000)	(551,000,000)
CASH AND CASH EQUIVALENTS AT BEGINNING OF YEAR	247,000,000	714,000,000
CASH AND CASH EQUIVALENTS AT END OF PERIOD	162,000,000	163,000,000
SUPPLEMENTARY CASH FLOW DATA:
Interest paid, net of capitalized interest	341,000,000	318,000,000
Income taxes paid, net of refunds	$ 153,000,000	$ 473,000,000

CONSOLIDATED BALANCE SHEET (Una

CONSOLIDATED BALANCE SHEET (Unaudited) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
CURRENT ASSETS:
Cash and cash equivalents ($2 and $6 related to Altus VIE)	$ 162	$ 247
Receivables, net of allowance of $95 and $88	899	1,062
Other current assets (Note 5) ($5 and $5 related to Altus VIE)	658	652
Total current assets	1,719	1,961
Oil and gas, on the basis of successful efforts accounting:
Proved properties	41,119	40,540
Unproved properties and properties under development	619	666
Gathering, processing, and transmission facilities ($212 and $203 related to Altus VIE)	677	799
Other ($3 and $4 related to Altus VIE)	1,138	1,140
Property and equipment, gross	43,553	43,145
Less: Accumulated depreciation, depletion, and amortization ($10 and $1 related to Altus VIE)	(34,486)	(28,987)
Property and equipment, net	9,067	14,158
OTHER ASSETS:
Equity method interests (Note 6) ($1,524 and $1,258 related to Altus VIE)	1,524	1,258
Deferred charges and other ($5 and $4 related to Altus VIE)	565	730
Total assets	12,875	18,107
CURRENT LIABILITIES:
Accounts payable	395	695
Current debt (nil and $10 related to Altus VIE)	184	11
Other current liabilities (Note 7) ($15 and $21 related to Altus VIE)	803	1,149
Total current liabilities	1,382	1,855
LONG-TERM DEBT (Note 10) ($580 and $396 related to Altus VIE)	8,750	8,555
DEFERRED CREDITS AND OTHER NONCURRENT LIABILITIES:
Income taxes	271	346
Asset retirement obligation (Note 8) ($63 and $60 related to Altus VIE)	1,859	1,811
Other ($184 and $107 related to Altus VIE)	650	520
Total deferred credits and other noncurrent liabilities	2,780	2,677
COMMITMENTS AND CONTINGENCIES (Note 11)
REDEEMABLE NONCONTROLLING INTEREST - ALTUS PREFERRED UNIT LIMITED PARTNERS (Note 12)	600	555
EQUITY:
Common stock, $0.625 par, 860,000,000 shares authorized, 418,409,054 and 417,026,863 shares issued, respectively	262	261
Paid-in capital	11,741	11,769
Accumulated deficit	(10,471)	(5,601)
Treasury stock, at cost, 40,948,811 and 40,964,193 shares, respectively	(3,189)	(3,190)
Accumulated other comprehensive income	16	16
APACHE SHAREHOLDERS’ EQUITY (DEFICIT)	(1,641)	3,255
TOTAL EQUITY (DEFICIT)	(637)	4,465
TOTAL LIABILITIES AND EQUITY	12,875	18,107
Noncontrolling interests, Egypt
EQUITY:
Noncontrolling interest	938	1,137
Noncontrolling interests, Altus
EQUITY:
Noncontrolling interest	$ 66	$ 73

CONSOLIDATED BALANCE SHEET (U_2

CONSOLIDATED BALANCE SHEET (Unaudited) (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Cash and cash equivalents	$ 162	$ 247
Receivables	899	1,062
Other current assets (Note 5) ($5 and $5 related to Altus VIE)	658	652
Gathering, transmission and processing facilities	677	799
Other	1,138	1,140
Less: Accumulated depreciation, depletion, and amortization	34,486	28,987
Equity method interests	1,524	1,258
Deferred charges and other	565	730
Current debt	184	11
Other current liabilities	803	1,149
Long-term debt	8,750	8,555
Asset retirement obligation	1,859	1,811
Other	$ 650	$ 520
Common stock, par value (in USD per share)	$ 0.625	$ 0.625
Common stock, shares authorized (in shares)	860,000,000	860,000,000
Common stock, shares issued (in shares)	418,409,054	417,026,863
Treasury stock, shares (in shares)	40,948,811	40,964,193
Altus VIE
Cash and cash equivalents	$ 2	$ 6
Receivables	95	88
Other current assets (Note 5) ($5 and $5 related to Altus VIE)	5	5
Gathering, transmission and processing facilities	212	203
Other	3	4
Less: Accumulated depreciation, depletion, and amortization	10	1
Equity method interests	1,524	1,258
Deferred charges and other	5	4
Current debt	0	10
Other current liabilities	15	21
Long-term debt	580	396
Asset retirement obligation	63	60
Other	$ 184	$ 107

STATEMENT OF CONSOLIDATED CHANG

STATEMENT OF CONSOLIDATED CHANGES IN EQUITY (DEFICIT) AND NONCONTROLLING INTEREST (Unaudited) - USD ($) $ in Millions	Total	Common Stock	Paid-In Capital	Accumulated Deficit	Treasury Stock	Accumulated Other Comprehensive Income (Loss)	APACHE SHAREHOLDERS’ EQUITY (DEFICIT)	Noncontrolling Interests	Noncontrolling interests, Egypt	Noncontrolling interests, Altus	Altus Preferred Unit limited partners
Beginning balance at Dec. 31, 2018											$ 0
Increase (Decrease) In Redeemable Noncontrolling Interest [Roll Forward]
Issuance of Altus Preferred Units											517
Net income attributable to Altus Preferred Unit limited partners											22
Ending balance at Sep. 30, 2019											539
Beginning balance at Dec. 31, 2018	$ 8,812	$ 260	$ 12,106	$ (2,048)	$ (3,192)	$ 4	$ 7,130	$ 1,682
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss attributable to common stock	(577)			(577)			(577)
Net income (loss) attributable to noncontrolling interest									$ 125	$ (5)	22
Distributions to noncontrolling interest - Egypt	(235)							(235)
Common dividends	(282)		(282)				(282)
Other	30	1	28		2		30
Ending balance at Sep. 30, 2019	7,868	261	11,852	(2,625)	(3,190)	3	6,301	1,567
Beginning balance at Jun. 30, 2019											521
Increase (Decrease) In Redeemable Noncontrolling Interest [Roll Forward]
Net income attributable to Altus Preferred Unit limited partners											18
Ending balance at Sep. 30, 2019											539
Beginning balance at Jun. 30, 2019	8,154	261	11,931	(2,455)	(3,190)	4	6,551	1,603
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss attributable to common stock	(170)			(170)			(170)
Net income (loss) attributable to noncontrolling interest									38	(3)	18
Distributions to noncontrolling interest - Egypt	(71)							(71)
Common dividends	(94)		(94)				(94)
Other	14		15				14
Ending balance at Sep. 30, 2019	7,868	261	11,852	(2,625)	(3,190)	3	6,301	1,567
Beginning balance at Dec. 31, 2019	555										555
Increase (Decrease) In Redeemable Noncontrolling Interest [Roll Forward]
Net income attributable to Altus Preferred Unit limited partners											56
Ending balance at Sep. 30, 2020	600										600
Beginning balance at Dec. 31, 2019	4,465	261	11,769	(5,601)	(3,190)	16	3,255	1,210
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss attributable to common stock	(4,870)			(4,870)			(4,870)
Net income (loss) attributable to noncontrolling interest									(138)	(7)	56
Distributions to noncontrolling interest - Egypt	(61)							(61)			(11)
Common dividends	(29)		(29)				(29)
Other	3	1	1		1	0	3
Ending balance at Sep. 30, 2020	(637)	262	11,741	(10,471)	(3,189)	16	(1,641)	1,004
Beginning balance at Jun. 30, 2020											592
Increase (Decrease) In Redeemable Noncontrolling Interest [Roll Forward]
Net income attributable to Altus Preferred Unit limited partners											19
Ending balance at Sep. 30, 2020	600										600
Beginning balance at Jun. 30, 2020	(636)	262	11,744	(10,467)	(3,189)	15	(1,635)	999
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss attributable to common stock	(4)			(4)			(4)
Net income (loss) attributable to noncontrolling interest									$ 24	$ 2	19
Distributions to noncontrolling interest - Egypt	(21)							(21)			$ (11)
Common dividends	(10)		(10)				(10)
Other	8		7				8
Ending balance at Sep. 30, 2020	$ (637)	$ 262	$ 11,741	$ (10,471)	$ (3,189)	$ 16	$ (1,641)	$ 1,004

STATEMENT OF CONSOLIDATED CHA_2

STATEMENT OF CONSOLIDATED CHANGES IN EQUITY (DEFICIT) AND NONCONTROLLING INTEREST (Unaudited) (Parenthetical) - $ / shares	1 Months Ended	2 Months Ended	3 Months Ended		9 Months Ended
	Mar. 31, 2020	Mar. 12, 2020	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement of Stockholders' Equity [Abstract]
Common stock, dividends, per share (in USD per share)	$ 0.025	$ 0.25	$ 0.025	$ 0.25	$ 0.075	$ 0.75

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	9 Months Ended
	Sep. 30, 2020
Accounting Policies [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES As of September 30, 2020 , Apache’s significant accounting policies are consistent with those discussed in Note 1—Summary of Significant Accounting Policies of the Notes to Consolidated Financial Statements contained in Apache’s Annual Report on Form 10-K for the fiscal year ended December 31, 2019 , with the exception of Accounting Standards Update (ASU) 2016-13, “Financial Instruments-Credit Losses” (see “Accounts Receivable and Allowance for Credit Losses” section in this Note 1 below). The Company’s financial statements for prior periods include reclassifications that were made to conform to the current-year presentation. Principles of Consolidation The accompanying consolidated financial statements include the accounts of Apache and its subsidiaries after elimination of intercompany balances and transactions. The Company’s undivided interests in oil and gas exploration and production ventures and partnerships are proportionately consolidated. The Company consolidates all other investments in which, either through direct or indirect ownership, Apache has more than a 50 percent voting interest or controls the financial and operating decisions. Noncontrolling interests represent third-party ownership in the net assets of a consolidated Apache subsidiary and are reflected separately in the Company’s financial statements. Sinopec International Petroleum Exploration and Production Corporation (Sinopec) owns a one-third minority participation in Apache’s Egypt oil and gas business as a noncontrolling interest, which is reflected as a separate component of equity in Apache’s consolidated balance sheet. Additionally, third-party investors own a minority interest of approximately 21 percent of Altus Midstream Company (ALTM), which is reflected as a separate noncontrolling interest component of equity in Apache’s consolidated balance sheet. ALTM qualifies as a variable interest entity (VIE) under GAAP. Apache consolidates the activities of ALTM because it has concluded that it has a controlling financial interest in ALTM and is the primary beneficiary of the VIE. On June 12, 2019, Altus Midstream LP issued and sold Series A Cumulative Redeemable Preferred Units (the Preferred Units) through a private offering that admitted additional limited partners with separate rights for the Preferred Unit holders. Refer to Note 12—Redeemable Noncontrolling Interest - Altus for more detail. Investments in which Apache holds less than 50 percent of the voting interest are typically accounted for under the equity method of accounting, with the balance recorded separately as “Equity method interests” in Apache’s consolidated balance sheet and results of operations recorded as a component of “Other, net” under “Revenues and Other” in the Company’s statement of consolidated operations. Refer to Note 6—Equity Method Interests for more detail. Use of Estimates Preparation of financial statements in conformity with GAAP and disclosure of contingent assets and liabilities requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. The Company bases its estimates on historical experience and various other assumptions that are believed to be reasonable under the circumstances, the results of which form the basis for making judgments about carrying values of assets and liabilities that are not readily apparent from other sources. Apache evaluates its estimates and assumptions on a regular basis. Actual results may differ from these estimates and assumptions used in preparation of its financial statements and changes in these estimates are recorded when known. Significant estimates with regard to these financial statements include the estimate of proved oil and gas reserves and related present value estimates of future net cash flows therefrom, the assessment of asset retirement obligations (see Note 8—Asset Retirement Obligation ), the estimates of fair value for long-lived assets (see “Fair Value Measurements,” “Oil and Gas Property,” and “Gathering, Processing, and Transmission Facilities” sections in this Note 1 below), and the estimate of income taxes (see Note 9—Income Taxes ). Actual results could differ from those estimates. Fair Value Measurements Certain assets and liabilities are reported at fair value on a recurring basis in Apache’s consolidated balance sheet. Accounting Standards Codification (ASC) 820-10-35, “Fair Value Measurement” (ASC 820), provides a hierarchy that prioritizes and defines the types of inputs used to measure fair value. The fair value hierarchy gives the highest priority to Level 1 inputs, which consist of unadjusted quoted prices for identical instruments in active markets. Level 2 inputs consist of quoted prices for similar instruments. Level 3 valuations are derived from inputs that are significant and unobservable; hence, these valuations have the lowest priority. Recurring fair value measurements are presented in further detail in Note 4—Derivative Instruments and Hedging Activities and Note 10—Debt and Financing Costs . Apache also uses fair value measurements on a nonrecurring basis when certain qualitative assessments of its assets indicate a potential impairment. The following table presents a summary of asset impairments recorded in connection with fair value assessments: For the Quarter Ended September 30, For the Nine Months Ended September 30, 2020 2019 2020 2019 (In millions) Oil and gas proved property $ — $ — $ 4,319 $ 86 Gathering, processing, and transmission facilities — 9 68 9 Goodwill — — 87 — Divested unproved properties and leasehold — — — 149 Inventory and other — — 18 5 Total Impairments $ — $ 9 $ 4,492 $ 249 The Company recorded no asset impairments in connection with fair value assessments in the third quarter of 2020. During the second quarter of 2020, the Company recorded asset impairments totaling $20 million in connection with fair value assessments on proved property in Egypt. These properties were impaired to their estimated fair values as a result of changes to planned development activity. During the first quarter of 2020, the Company recorded asset impairments totaling $4.5 billion in connection with fair value assessments. Given the crude oil price collapse on lower demand and economic activity resulting from the coronavirus disease 2019 (COVID-19) global pandemic and related governmental actions, the Company assessed its oil and gas property and gathering, processing, and transmission (GPT) assets for impairment based on the net book value of its assets as of March 31, 2020. The Company recorded proved property impairments totaling $3.9 billion , $354 million , and $7 million in the U.S., Egypt, and offshore the United Kingdom in the North Sea (North Sea), respectively, all of which were impaired to their estimated fair values as a result of lower forecasted commodity prices, changes to planned development activity, and increasing market uncertainty. The first and second quarter property impairments are discussed in further detail below in “Oil and Gas Property.” Impairments totaling $68 million were similarly recorded for GPT facilities in Egypt. This impairment is discussed in further detail below in “Gathering, Processing, and Transmission Facilities.” During the first quarter of 2020, the Company performed an interim impairment analysis of the goodwill related to its Egypt reporting unit under ASU 2017-04, “Simplifying the Test for Goodwill Impairment,” which was adopted during the quarter. Reductions in estimated net present value of expected future cash flows from oil and gas properties resulted in implied fair values below the carrying values of the Company’s Egypt reporting unit. As a result of these assessments, the Company recognized non-cash impairments of the entire amount of recorded goodwill in the Egypt reporting unit of $87 million . During the first quarter of 2020, the Company also recorded impairments of $13 million for the early termination of drilling rig leases and $5 million for inventory revaluations, both in the U.S. During the third quarter of 2019, the Company’s Altus Midstream reporting segment recorded an impairment charge of $9 million related to the cancellation of construction on a previously planned compressor station based on estimated sales proceeds for the associated equipment. The estimated fair value of the assets held for sale was approximately $18 million and was determined using a market approach based on proceeds expected to be received, a Level 1 fair value measurement. In the second quarter of 2019, the Company entered into an agreement to sell certain of its assets in the Western Anadarko Basin in Oklahoma and Texas. As a result of this agreement, a separate impairment analysis was performed for each of the assets within the disposal group. The analyses were based on the agreed-upon proceeds less costs to sell for the transaction, a Level 1 fair value measurement. The carrying value of the net assets to be divested exceeded the fair value implied by the expected net proceeds, resulting in impairments totaling $240 million , including $86 million on the Company’s proved properties, $149 million on its unproved properties, and $5 million on other working capital. See Note 2—Acquisitions and Divestitures for more detail. Oil and Gas Property The Company follows the successful efforts method of accounting for its oil and gas property. Under this method of accounting, exploration costs, such as exploratory geological and geophysical costs, delay rentals, and exploration overhead, are expensed as incurred. All costs related to production, general corporate overhead, and similar activities are expensed as incurred. If an exploratory well provides evidence to justify potential development of reserves, drilling costs associated with the well are initially capitalized, or suspended, pending a determination as to whether a commercially sufficient quantity of proved reserves can be attributed to the area as a result of drilling. This determination may take longer than one year in certain areas depending on, among other things, the amount of hydrocarbons discovered, the outcome of planned geological and engineering studies, the need for additional appraisal drilling activities to determine whether the discovery is sufficient to support an economic development plan, and government sanctioning of development activities in certain international locations. At the end of each quarter, management reviews the status of all suspended exploratory well costs in light of ongoing exploration activities; in particular, whether the Company is making sufficient progress in its ongoing exploration and appraisal efforts or, in the case of discoveries requiring government sanctioning, whether development negotiations are underway and proceeding as planned. If management determines that future appraisal drilling or development activities are unlikely to occur, associated suspended exploratory well costs are expensed. Acquisition costs of unproved properties are assessed for impairment at least annually and are transferred to proved oil and gas properties to the extent the costs are associated with successful exploration activities. Significant undeveloped leases are assessed individually for impairment based on the Company’s current exploration plans. Unproved oil and gas properties with individually insignificant lease acquisition costs are amortized on a group basis over the average lease term at rates that provide for full amortization of unsuccessful leases upon lease expiration or abandonment. Costs of expired or abandoned leases are charged to exploration expense, while costs of productive leases are transferred to proved oil and gas properties. Costs of maintaining and retaining unproved properties, as well as amortization of individually insignificant leases and impairment of unsuccessful leases, are included in exploration costs in the statement of consolidated operations. Costs to develop proved reserves, including the costs of all development wells and related equipment used in the production of crude oil and natural gas, are capitalized. Depreciation of the cost of proved oil and gas properties is calculated using the unit-of-production (UOP) method. The UOP calculation multiplies the percentage of estimated proved reserves produced each quarter by the carrying value of associated proved oil and gas properties. The reserve base used to calculate depreciation for leasehold acquisition costs and the cost to acquire proved properties is the sum of proved developed reserves and proved undeveloped reserves. The reserve base used to calculate the depreciation for capitalized well costs is the sum of proved developed reserves only. Estimated future dismantlement, restoration and abandonment costs, net of salvage values, are included in the depreciable cost. Oil and gas properties are grouped for depreciation in accordance with ASC 932, “Extractive Activities—Oil and Gas.” The basis for grouping is a reasonable aggregation of properties with a common geological structural feature or stratigraphic condition, such as a reservoir or field. When circumstances indicate that the carrying value of proved oil and gas properties may not be recoverable, the Company compares unamortized capitalized costs to the expected undiscounted pre-tax future cash flows for the associated assets grouped at the lowest level for which identifiable cash flows are independent of cash flows of other assets. If the expected undiscounted pre-tax future cash flows, based on Apache’s estimate of future crude oil and natural gas prices, operating costs, anticipated production from proved reserves and other relevant data, are lower than the unamortized capitalized cost, the capitalized cost is reduced to fair value. Fair value is generally estimated using the income approach described in ASC 820. The expected future cash flows used for impairment reviews and related fair value calculations are typically based on judgmental assessments, a Level 3 fair value measurement. The significant decline in oil and natural gas prices, as well as longer-term commodity price outlooks, related to reduced demand for oil and natural gas as a result of the COVID-19 pandemic and related governmental actions indicated possible impairment of the Company’s proved and unproved oil and gas properties. In addition to estimating risk-adjusted reserves and future production volumes, estimated future commodity prices are the largest driver in variability of undiscounted pre-tax cash flows. Expected cash flows were estimated based on management’s views of published West Texas Intermediate (WTI), Brent, and Henry Hub forward pricing as of the balance sheet dates. Other significant assumptions and inputs used to calculate estimated future cash flows include estimates for future development activity, exploration plans and remaining lease terms. A 10 percent discount rate, based on a market-based weighted-average cost of capital estimate, was applied to the undiscounted cash flow estimate to value all of Apache’s asset groups that were subject to impairment charges in the first and second quarters of 2020. The following table represents non-cash impairments of the carrying value of the Company’s proved and unproved properties: For the Quarter Ended September 30, For the Nine Months Ended September 30, 2020 2019 2020 2019 (In millions) Proved Properties: U.S. $ — $ — $ 3,938 $ 86 Egypt — — 374 — North Sea — — 7 — Total Proved $ — $ — $ 4,319 $ 86 Unproved Properties: U.S. $ 34 $ 10 $ 80 $ 217 Egypt 2 2 6 6 Total Unproved $ 36 $ 12 $ 86 $ 223 Proved properties impaired during the second and first quarters of 2020 had aggregate fair values of $32 million and $1.9 billion , respectively. On the statement of consolidated operations, unproved leasehold impairments are typically recorded as a component of “Exploration” expense; however, in the second quarter of 2019, unproved impairments of $149 million were recorded in “Impairments” in connection with the Company’s agreement to sell certain non-core leasehold properties in Oklahoma and Texas. Gains and losses on divestitures of the Company’s oil and gas properties are recognized in the statement of consolidated operations upon closing of the transaction. See Note 2—Acquisitions and Divestitures for more detail. Gathering, Processing, and Transmission Facilities The Company assesses the carrying amount of its GPT facilities whenever events or changes in circumstances indicate that their carrying amount may not be recoverable. If the carrying amount of these facilities is more than the sum of the undiscounted cash flows, an impairment loss is recognized for the excess of the carrying value over its fair value. As discussed under “Fair Value Measurements” above, Apache assessed its long-lived infrastructure assets for impairment at March 31, 2020, and recorded an impairment of $68 million on its GPT assets in Egypt during the first quarter of 2020. The fair values of the impaired assets were determined to be $46 million and were estimated using the income approach. The income approach considered internal estimates based on future throughput volumes from applicable development concessions in Egypt and estimated costs to operate. These assumptions were applied based on throughput assumptions developed in relation to the oil and gas proved property impairment assessment as discussed above to develop future cash flow projections that were then discounted to estimated fair value, using a 10 percent discount rate, based on a market-based weighted-average cost of capital estimate. Apache has classified these non-recurring fair value measurements as Level 3 in the fair value hierarchy. As discussed under “Fair Value Measurements” above, in the third quarter of 2019 Altus recorded an impairment charge of $9 million related to the cancellation of construction on a previously planned compressor station based on estimated sales proceeds for the associated equipment. The estimated fair value of the assets held for sale was approximately $18 million and was determined using a market approach based on proceeds expected to be received, a Level 1 fair value measurement. Revenue Recognition There have been no significant changes to the Company’s contracts with customers during the nine months ended September 30, 2020 and 2019 . The third quarter and first nine months of 2019 include the reclassification of $30 million and $72 million , respectively, from “Other, net” to “Purchased oil and gas sales,” both within “Revenues and Other” and the respective associated $23 million and $60 million purchased oil and gas costs from “Other, net” within “Revenues and Other” to “Purchased oil and gas costs” within “Operating Expenses” on the Company’s consolidated statement of operations to conform to the current-year presentation. Upstream The Company’s upstream oil and gas segments primarily generate revenue from contracts with customers from the sale of its crude oil, natural gas, and natural gas liquids (NGLs) production volumes. Because the Company’s production fluctuates with potential operational issues and changes to development plans, Apache purchases third-party oil and gas to fulfill sales obligations and commitments. Sales proceeds related to third-party oil and gas purchases are also classified as revenue from customers. Under these short-term commodity sales contracts, the physical delivery of each unit of quantity represents a single, distinct performance obligation on behalf of the Company. Contract prices are determined based on market-indexed prices, adjusted for quality, transportation, and other market-reflective differentials. Revenue is measured by allocating an entirely variable market price to each performance obligation and recognized at a point in time when control is transferred to the customer. The Company considers a variety of facts and circumstances in assessing the point of control transfer, including but not limited to: whether the purchaser can direct the use of the hydrocarbons, the transfer of significant risks and rewards, and the Company’s right to payment. Control typically transfers to customers upon the physical delivery at specified locations within each contract and the transfer of title. Oil and gas production revenues from non-customers represent income taxes paid to the Arab Republic of Egypt by Egyptian General Petroleum Corporation on behalf of the Company. Revenue and associated expenses related to such tax volumes are recorded as “Oil, natural gas, and natural gas liquids production revenues” and “Current income tax provision,” respectively, in the Company’s statement of consolidated operations. Refer to Note 14—Business Segment Information for a disaggregation of revenue by product and reporting segment. Altus Midstream The Company’s Altus Midstream segment is operated by ALTM, through its subsidiary, Altus Midstream LP (collectively, Altus), and generates revenue from contracts with its customers from its gathering, compression, processing, and transmission services. These services are primarily provided on Apache’s natural gas and natural gas liquid production volumes. Under these long-term commercial service contracts, providing the related service represents a single, distinct performance obligation on behalf of Altus that is satisfied over time. In accordance with the terms of these agreements, Altus receives a fixed fee for each contract year, subject to yearly fee escalation recalculations. Revenue is measured using the output method and recognized in the amount to which Altus has the right to invoice, as performance completed to date corresponds directly with the value to its customers. For the periods presented, midstream segment revenues were primarily attributable to sales between Altus and Apache. All midstream revenues between Apache and Altus are fully eliminated upon consolidation. Payment Terms and Contract Balances Payments under all contracts with customers are typically due and received within a short-term period of one year or less, after physical delivery of the product or service has been rendered. Receivables from contracts with customers, net of allowance for credit losses, totaled $770 million and $945 million as of September 30, 2020 and December 31, 2019 , respectively. In accordance with the provisions of ASC 606, “Revenue from Contracts with Customers,” variable market prices for each short-term commodity sale are allocated entirely to each performance obligation as the terms of payment relate specifically to the Company’s efforts to satisfy its obligations. As such, the Company has elected the practical expedients available under the standard to not disclose the aggregate transaction price allocated to unsatisfied, or partially unsatisfied, performance obligations as of the end of the reporting period. Accounts Receivable and Allowance for Credit Losses Accounts receivable are stated at amortized cost net of an allowance for credit losses. The Company routinely assesses the collectability of its financial assets measured at amortized cost. In June 2016, the Financial Accounting Standards Board (FASB) issued ASU 2016-13, “Financial Instruments-Credit Losses.” The standard changes the impairment model for trade receivables, held-to-maturity debt securities, net investments in leases, loans, and other financial assets measured at amortized cost. This ASU requires the use of a new forward-looking “expected loss” model compared to the previous “incurred loss” model, resulting in accelerated recognition of credit losses. Apache adopted this update in the first quarter of 2020. This ASU primarily applies to the Company’s accounts receivable balances, of which the majority are due within 30 days. The Company monitors the credit quality of its counterparties through review of collections, credit ratings, and other analyses. The Company develops its estimated allowance for credit losses primarily using an aging method and analyses of historical loss rates as well as consideration of current and future conditions that could impact its counterparties’ credit quality and liquidity. The adoption and implementation of this ASU did not have a material impact on the Company’s financial statements. Transaction, Reorganization, and Separation (TRS) Apache recorded $7 million of TRS costs during each of the third quarters of 2020 and 2019 and $44 million and $17 million during the first nine months of 2020 and 2019, respectively. TRS costs incurred in the third quarter of 2020 relate to separation costs associated with the Company’s reorganization. TRS costs incurred in the first nine months of 2020 relate to $41 million of separation costs related to the reorganization, $2 million for transaction consulting fees, and $1 million of office closure costs. TRS costs incurred in the third quarter and first nine months of 2019 were primarily related to separation costs and consulting fees on various transactions. In recent years, the Company has streamlined its portfolio through strategic divestitures and began centralizing certain operational activities in an effort to capture greater efficiencies and cost savings through shared services. During the second half of 2019, management initiated a comprehensive redesign of Apache’s organizational structure and operations. Reorganization efforts were substantially completed during the first half of 2020. Apache has incurred a cumulative total of $69 million of reorganization costs through September 30, 2020 , all of which was paid in the first nine months of 2020. New Pronouncements Issued but Not Yet Adopted In August 2020, the FASB issued ASU 2020-06, “Debt-Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging-Contracts in Entity’s Own Equity (Subtopic 815-40)” to improve financial reporting associated with accounting for convertible instruments and contracts in an entity’s own equity. This update is effective for Apache beginning in the first quarter of 2022, with early adoption permitted, using either the modified or fully retrospective method with a cumulative effect adjustment to the opening balance of retained earnings. The Company is evaluating the effect of adoption of the ASU and does not believe it will have a material impact on its financial statements.

ACQUISITIONS AND DIVESTITURES

ACQUISITIONS AND DIVESTITURES	9 Months Ended
	Sep. 30, 2020
Business Combinations [Abstract]
ACQUISITIONS AND DIVESTITURES	ACQUISITIONS AND DIVESTITURES 2020 Activity The Company had no leasehold or property acquisitions during the third quarter of 2020. During the first nine months of 2020 , Apache completed leasehold and property acquisitions for total cash consideration of $3 million that were primarily in the Permian Basin. During the first nine months of 2020, the Company also completed the sale of certain non-core assets and leasehold, primarily in the Permian Basin, in multiple transactions for total cash proceeds of $53 million . The Company recognized a gain of approximately $5 million upon closing of these transactions. Suriname Joint Venture Agreement In December 2019, Apache entered into a joint venture agreement with Total S.A. to explore and develop Block 58 offshore Suriname. Under the terms of the agreement, Apache and Total S.A. each hold a 50 percent working interest in Block 58. Apache operated the drilling of the first four wells, the Maka Central-1, Sapakara West-1, Kwaskwasi-1, and Keskesi East-1. Operatorship will subsequently transfer to Total. In connection with the agreement, Apache received $100 million from Total S.A. upon closing in the fourth quarter of 2019 and $79 million upon satisfying certain closing conditions in the first quarter of 2020 for reimbursement of 50 percent of all costs incurred on Block 58 as of December 31, 2019. All proceeds were applied against the carrying value of the Company’s Suriname properties and associated inventory. The Company recognized a $19 million gain in the first quarter of 2020 associated with the transaction. Apache will also receive various other forms of consideration, including $5 billion of cash carry on Apache’s first $7.5 billion of appraisal and development capital, 25 percent cash carry on all of Apache’s appraisal and development capital beyond the first $7.5 billion , a $75 million cash payment upon achieving first oil production, and future contingent royalty payments from successful joint development projects. 2019 Activity In the third quarter of 2019, Apache completed the sale of non-core assets in the western Anadarko Basin of Oklahoma and Texas for aggregate cash proceeds of approximately $322 million and the assumption of asset retirement obligations of $49 million . These assets met the criteria to be classified as held for sale in the second quarter of 2019. Accordingly, the Company performed a fair value assessment of the assets and recorded impairments of $240 million to the carrying value of proved and unproved oil and gas properties, other fixed assets, and working capital. The transaction closed in the third quarter of 2019, and the Company recognized a $7 million loss in connection with the sale. In the second quarter of 2019, Apache completed the sale of certain non-core assets in Oklahoma that had a net carrying value of $206 million for aggregate cash proceeds of approximately $223 million . The Company recognized a $17 million gain in connection with the sale. During the first nine months of 2019, the Company also completed the sale of certain other non-core producing assets and leasehold, primarily in the Permian region, in multiple transactions for total cash proceeds of $21 million . The Company recognized a net gain of approximately $12 million upon closing of these transactions. During the third quarter and first nine months of 2019, Apache completed leasehold and property acquisitions for total cash consideration of $5 million and $39 million , respectively, primarily in the Permian Basin. For discussion on the Company’s acquisition of equity method interests during the period, refer to Note 6—Equity Method Interests .

CAPITALIZED EXPLORATORY WELL CO

CAPITALIZED EXPLORATORY WELL COSTS	9 Months Ended
	Sep. 30, 2020
Extractive Industries [Abstract]
CAPITALIZED EXPLORATORY WELL COSTS	CAPITALIZED EXPLORATORY WELL COSTS The Company’s capitalized exploratory well costs were $195 million and $141 million at September 30, 2020 and December 31, 2019 , respectively. The increase is primarily attributable to additional drilling activity, partially offset by transfer of successful well costs and dry hole write-offs. Dry hole expenses from suspended exploratory well costs previously capitalized for greater than one year at December 31, 2019 totaled $14 million during the nine months ended September 30, 2020 . Projects with suspended exploratory well costs capitalized for a period greater than one year since the completion of drilling are those identified by management as exhibiting sufficient quantities of hydrocarbons to justify potential development. Management is actively pursuing efforts to assess whether proved reserves can be attributed to these projects.

DERIVATIVE INSTRUMENTS AND HEDG

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES	9 Months Ended
	Sep. 30, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES	DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES Objectives and Strategies The Company is exposed to fluctuations in crude oil and natural gas prices on the majority of its worldwide production, as well as transactions denominated in foreign currencies. The Company manages the variability in its cash flows by occasionally entering into derivative transactions on a portion of its crude oil and natural gas production and foreign currency transactions. The Company also utilizes various types of derivative financial instruments to manage fluctuations in cash flows resulting from changes in commodity prices or foreign currency values. Counterparty Risk The use of derivative instruments exposes the Company to credit loss in the event of nonperformance by the counterparty. To reduce the concentration of exposure to any individual counterparty, Apache utilizes a diversified group of investment-grade rated counterparties, primarily financial institutions, for its derivative transactions. As of September 30, 2020 , Apache had derivative positions with 12 counterparties. The Company monitors counterparty creditworthiness on an ongoing basis; however, it cannot predict sudden changes in counterparties’ creditworthiness. In addition, even if such changes are not sudden, the Company may be limited in its ability to mitigate an increase in counterparty credit risk. Should one of these counterparties not perform, Apache may not realize the benefit of some of its derivative instruments resulting from changes in commodity prices, currency exchange rates, or interest rates. Derivative Instruments Commodity Derivative Instruments As of September 30, 2020 , Apache had the following open crude oil derivative positions: Collars Production Period Settlement Index Mbbls Weighted Average Floor Sold Price Weighted Average Floor Purchased Price Weighted Average Ceiling Price October—December 2020 NYMEX WTI 1,748 $15.00 $20.00 $45.55 October—December 2020 Dated Brent 1,518 $15.00 $20.00 $51.63 As of September 30, 2020 , Apache had the following open crude oil financial basis swap contracts: Basis Swap Purchased Basis Swap Sold Production Period Settlement Index Mbbls Weighted Average Price Differential Mbbls Weighted Average Price Differential October—December 2020 Midland-WTI/Cushing-WTI — — 6,716 $(2.15) October—December 2020 Midland-WTI/Cushing-WTI 828 $0.20 — — As of September 30, 2020 , Apache had the following open natural gas financial basis swap contracts: Basis Swap Purchased Basis Swap Sold Production Period Settlement Index MMBtu (in 000’s) Weighted Average Price Differential MMBtu (in 000’s) Weighted Average Price Differential April—December 2021 Nymex Henry Hub/IF Waha 37,580 $(0.43) — — April—December 2021 Nymex Henry Hub/IF HSC — — 37,580 $(0.07) January—December 2022 Nymex Henry Hub/IF Waha 43,800 $(0.45) — — January—December 2022 Nymex Henry Hub/IF HSC — — 43,800 $(0.08) Foreign Currency Derivative Instruments Apache has open foreign currency costless collar contracts in GBP/USD for £13.5 million per month for the calendar year 2020 with a weighted average floor and ceiling price of $1.26 and $1.38 , respectively. Embedded Derivatives Altus Preferred Units Embedded Derivative During the second quarter of 2019, Altus Midstream LP issued and sold Preferred Units. Certain redemption features embedded within the Preferred Units require bifurcation and measurement at fair value. For further discussion of this derivative, see “Fair Value Measurements” below and Note 12—Redeemable Noncontrolling Interest - Altus . Pipeline Capacity Embedded Derivatives During the fourth quarter of 2019 and first quarter of 2020, Apache entered into separate agreements to assign a portion of its contracted capacity under an existing transportation agreement to third parties. Embedded in these agreements are arrangements under which Apache has the potential to receive payments calculated based on pricing differentials between Houston Ship Channel and Waha during calendar years 2020 and 2021. These features require bifurcation and measurement of the change in market values for each period. Unrealized gains or losses in the fair value of these features are recorded as “Derivative instrument losses, net” under “Revenues and Other” in the statement of consolidated operations. Any proceeds received will be deferred and reflected in income over the original tenure of the transportation agreement. Fair Value Measurements The following table presents the Company’s derivative assets and liabilities measured at fair value on a recurring basis: Fair Value Measurements Using Quoted Price in Active Markets (Level 1) Significant Other Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total Fair Value Netting (1) Carrying Amount (In millions) September 30, 2020 Assets: Commodity Derivative Instruments $ — $ 12 $ — $ 12 $ (2 ) $ 10 Liabilities: Commodity Derivative Instruments $ — $ 15 $ — $ 15 $ (2 ) $ 13 Pipeline Capacity Embedded Derivatives — 54 — 54 — 54 Foreign Currency Derivative Instruments — 1 — 1 — 1 Preferred Units Embedded Derivative — — 179 179 — 179 December 31, 2019 Assets: Pipeline Capacity Embedded Derivative $ — $ 8 $ — $ 8 $ — $ 8 Foreign Currency Derivative Instruments — 1 — 1 — 1 Liabilities: Preferred Units Embedded Derivative — — 103 103 — 103 (1) The derivative fair values are based on analysis of each contract on a gross basis, excluding the impact of netting agreements with counterparties. The fair values of the Company’s derivative instruments and pipeline capacity embedded derivatives are not actively quoted in the open market. The Company primarily uses a market approach to estimate the fair values of these derivatives on a recurring basis, utilizing futures pricing for the underlying positions provided by a reputable third party, a Level 2 fair value measurement. The fair value of the Preferred Units embedded derivative, a Level 3 fair value measurement, was based on numerous factors, including expected future interest rates using the Black-Karasinski model, Altus’ imputed interest rate, the timing of periodic cash distributions, and dividend yields of the Preferred Units. Increases or decreases in interest rates would result in a higher/lower fair value measurement. As of the September 30, 2020 valuation date, the Company used the forward B-rated Energy Bond Yield curve to develop the following key unobservable inputs used to value this embedded derivative: Quantitative Information About Level 3 Fair Value Measurements Fair Value at September 30, 2020 Valuation Technique Significant Unobservable Inputs Range/Value (In millions) Preferred Units Embedded Derivative $ 179 Option Model Altus’ Imputed Interest Rate 14.54-16.18% Interest Rate Volatility 35.32% Altus’ comparative imputed interest rate at December 31, 2019 ranged from 9.60 percent to 12.68 percent , with an interest rate volatility assumption of 21.89 percent . A one percent increase in the imputed interest rate assumption would significantly increase the value of the embedded derivative as of September 30, 2020 , while a one percent decrease would have the directionally inverse affect as of September 30, 2020 . All derivative instruments are reflected as either assets or liabilities at fair value in the consolidated balance sheet. These fair values are recorded by netting asset and liability positions where counterparty master netting arrangements contain provisions for net settlement. The carrying value of the Company’s derivative assets and liabilities and their locations on the consolidated balance sheet are as follows: September 30, 2020 December 31, 2019 (In millions) Current Assets: Other current assets $ 1 $ 2 Other Assets: Deferred charges and other 9 7 Total Assets $ 10 $ 9 Current Liabilities: Other current liabilities $ 14 $ — Deferred Credits and Other Noncurrent Liabilities: Other 233 103 Total Liabilities $ 247 $ 103 Derivative Activity Recorded in the Statement of Consolidated Operations The following table summarizes the effect of derivative instruments on the Company’s statement of consolidated operations: For the Quarter Ended September 30, For the Nine Months Ended September 30, 2020 2019 2020 2019 (In millions) Realized: Commodity derivative instruments $ (83 ) $ (16 ) $ (119 ) $ 30 Foreign currency derivative instruments — — (1 ) — Treasury-lock — — — (18 ) Realized gain (loss), net (83 ) (16 ) (120 ) 12 Unrealized: Commodity derivative instruments 91 (3 ) (3 ) (69 ) Pipeline capacity embedded derivatives 8 — (62 ) — Foreign currency derivative instruments 3 21 (1 ) 21 Preferred units embedded derivative (3 ) (4 ) (76 ) (4 ) Unrealized gain (loss), net 99 14 (142 ) (52 ) Derivative instrument gains (losses), net $ 16 $ (2 ) $ (262 ) $ (40 ) Derivative instrument gains and losses are recorded in “Derivative instrument gains (losses), net” under “Revenues and Other” in the Company’s statement of consolidated operations. Unrealized gains (losses) for derivative activity recorded in the statement of consolidated operations are reflected in the statement of consolidated cash flows separately as “Unrealized derivative instrument losses, net” in “Adjustments to reconcile net loss to net cash provided by operating activities.”

OTHER CURRENT ASSETS

OTHER CURRENT ASSETS	9 Months Ended
	Sep. 30, 2020
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
OTHER CURRENT ASSETS	OTHER CURRENT ASSETS The following table provides detail of the Company’s other current assets as of September 30, 2020 and December 31, 2019 : September 30, 2020 December 31, 2019 (In millions) Inventories $ 503 $ 502 Drilling advances 102 92 Prepaid assets and other 53 58 Total Other current assets $ 658 $ 652

EQUITY METHOD INTERESTS

EQUITY METHOD INTERESTS	9 Months Ended
	Sep. 30, 2020
Equity Method Investments and Joint Ventures [Abstract]
EQUITY METHOD INTERESTS	EQUITY METHOD INTERESTS Apache, through its ownership of Altus, has the following equity method interests in four Permian Basin long-haul pipeline entities, which are accounted for under the equity method of accounting. For each of the equity method interests, Altus has the ability to exercise significant influence based on certain governance provisions and its participation in activities and decisions that impact the management and economic performance of the equity method interests. Interest September 30, 2020 December 31, 2019 (In millions) Gulf Coast Express Pipeline LLC 16.0 % $ 284 $ 291 EPIC Crude Holdings, LP 15.0 % 182 163 Permian Highway Pipeline LLC 26.7 % 576 311 Breviloba, LLC (Shin Oak Pipeline) 33.0 % 482 493 $ 1,524 $ 1,258 As of September 30, 2020 and December 31, 2019 , unamortized basis differences included in the equity method interest balances were $37 million and $30 million , respectively. These amounts represent differences in contributions to date and Altus’ underlying equity in the separate net assets within the financial statements of the respective entities. Unamortized basis differences are amortized into net income over the useful lives of the underlying pipeline assets when they are placed into service. The following table presents the activity in Altus’ equity method interests for the nine months ended September 30, 2020 : Gulf Coast Express Pipeline LLC EPIC Crude Holdings, LP Permian Highway Pipeline LLC Breviloba, LLC Total (In millions) Balance at December 31, 2019 $ 291 $ 163 $ 311 $ 493 $ 1,258 Capital contributions 1 27 258 — 286 Distributions (39 ) — — (35 ) (74 ) Capitalized interest — — 7 — 7 Equity income (loss), net 31 (8 ) — 24 47 Balance at September 30, 2020 $ 284 $ 182 $ 576 $ 482 $ 1,524 Summarized Combined Financial Information The following presents summarized information of combined statement of operations for Altus’ equity method interests (on a 100 percent basis): For the Nine Months Ended September 30, 2020 2019 (1) (In millions) Operating revenues $ 531 $ 103 Operating expenses 264 62 Operating income 267 41 Net income 217 34 Other comprehensive loss (1 ) (11 ) (1) Although Altus’ interests in EPIC Crude Holdings, LP, Permian Highway Pipeline LLC, and Breviloba, LLC were acquired in March, May, and July 2019, respectively, the combined financial results are presented for the nine months ended September 30, 2019 for comparability.

OTHER CURRENT LIABILITIES

OTHER CURRENT LIABILITIES	9 Months Ended
	Sep. 30, 2020
Payables and Accruals [Abstract]
OTHER CURRENT LIABILITIES	OTHER CURRENT LIABILITIES The following table provides detail of the Company’s other current liabilities as of September 30, 2020 and December 31, 2019 : September 30, 2020 December 31, 2019 (In millions) Accrued operating expenses $ 99 $ 143 Accrued exploration and development 158 319 Accrued gathering, processing, and transmission - Altus 1 17 Accrued compensation and benefits 116 212 Accrued interest 111 135 Accrued income taxes 18 51 Current asset retirement obligation 47 47 Current operating lease liability 110 169 Current derivative liability 14 — Other 129 56 Total Other current liabilities $ 803 $ 1,149

ASSET RETIREMENT OBLIGATION

ASSET RETIREMENT OBLIGATION	9 Months Ended
	Sep. 30, 2020
Asset Retirement Obligation Disclosure [Abstract]
ASSET RETIREMENT OBLIGATION	ASSET RETIREMENT OBLIGATION The following table describes changes to the Company’s asset retirement obligation (ARO) liability for the nine -month period ended September 30, 2020 : (In millions) Asset retirement obligation at December 31, 2019 $ 1,858 Liabilities incurred 10 Liabilities settled (23 ) Liabilities divested (20 ) Accretion expense 81 Asset retirement obligation at September 30, 2020 1,906 Less current portion (47 ) Asset retirement obligation, long-term $ 1,859

INCOME TAXES

INCOME TAXES	9 Months Ended
	Sep. 30, 2020
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES The Company estimates its annual effective income tax rate in recording its quarterly provision for income taxes in the various jurisdictions in which the Company operates. Non-cash impairments of the carrying value of the Company’s oil and gas properties, gains and losses on the sale of assets, statutory tax rate changes, and other significant or unusual items are recognized as discrete items in the quarter in which they occur. During the third quarters of 2020 and 2019, Apache’s effective income tax rate was primarily impacted by an increase in the amount of valuation allowance against its U.S. deferred tax assets. Apache’s 2020 year-to-date effective income tax rate was primarily impacted by oil and gas asset impairments, a goodwill impairment, and an increase in the amount of valuation allowance against its U.S. deferred tax assets. Apache’s 2019 year-to-date effective income tax rate was primarily impacted by an increase in the amount of valuation allowance against the Company’s U.S. deferred tax assets. In the first quarter of 2020, the Company early adopted ASU 2019-12, “Simplifying the Accounting for Income Taxes.” The Company’s early adoption of ASU 2019-12 during the quarter ended March 31, 2020 using the prospective transition approach did not result in a material impact on the consolidated financial statements. Apache and its subsidiaries are subject to U.S. federal income tax as well as income or capital taxes in various state and foreign jurisdictions. The Company’s tax reserves are related to tax years that may be subject to examination by the relevant taxing authority. The Company is currently under audit by the Internal Revenue Service (IRS) for the 2014-2017 tax years and is also under audit in various states and foreign jurisdictions as part of its normal course of business.

DEBT AND FINANCING COSTS

DEBT AND FINANCING COSTS	9 Months Ended
	Sep. 30, 2020
Debt Disclosure [Abstract]
DEBT AND FINANCING COSTS	DEBT AND FINANCING COSTS The following table presents the carrying value of the Company’s debt: September 30, 2020 December 31, 2019 (In millions) Notes and debentures before unamortized discount and debt issuance costs (1) $ 8,324 $ 8,217 Altus credit facility (2) 580 396 Apache credit facility (2) 87 — Finance lease obligations 37 48 Unamortized discount (35 ) (42 ) Debt issuance costs (59 ) (53 ) Total debt 8,934 8,566 Current maturities (184 ) (11 ) Long-term debt $ 8,750 $ 8,555 (1) The fair values of the Company’s notes and debentures were $7.6 billion and $8.4 billion as of September 30, 2020 and December 31, 2019 , respectively. Apache uses a market approach to determine the fair values of its notes and debentures using estimates provided by an independent investment financial data services firm (a Level 2 fair value measurement). (2) The carrying amount of borrowings on credit facilities approximates fair value because the interest rates are variable and reflective of market rates. As of September 30, 2020 , current debt included $183 million , net of discount, of 3.625% senior notes due February 1, 2021 and $1 million of finance lease obligations. On November 3, 2020, the Company redeemed the 3.625% senior notes due February 1, 2021 at a redemption price equal to 100 percent of their principal amount, plus accrued and unpaid interest to the redemption date. As of December 31, 2019 , current debt included $11 million of finance lease obligations. On August 17, 2020, the Company closed offerings of $1.25 billion in aggregate principal amount of senior unsecured notes, comprised of $500 million in aggregate principal amount of 4.625% notes due 2025 and $750 million in aggregate principal amount of 4.875% notes due 2027. The senior unsecured notes are redeemable at any time, in whole or in part, at Apache’s option, at the applicable redemption price. The net proceeds from the sale of the notes were used to purchase certain outstanding notes in cash tender offers, repay a portion of outstanding borrowings under the Company’s senior revolving credit facility, and for general corporate purposes. On August 18, 2020, the Company closed cash tender offers for certain outstanding notes. Apache accepted for purchase $644 million aggregate principal amount of certain notes covered by the tender offers. Apache paid holders an aggregate $644 million , reflecting principal, aggregate discount to par of $38 million , early tender premium of $32 million , and accrued and unpaid interest of $6 million . The Company recorded a net gain of $2 million on extinguishment of debt, including an acceleration of unamortized debt discount and issuance costs, in connection with the note purchases. During the quarter ended September 30, 2020, the Company purchased in the open market and canceled senior notes issued under its indentures in an aggregate principal amount of $89 million for an aggregate purchase price of $79 million in cash, including accrued interest and broker fees, reflecting a discount to par of an aggregate $11 million . These repurchases resulted in a $10 million net gain on extinguishment of debt. The net gain includes an acceleration of related discount and debt issuance costs. The repurchases were financed by borrowings under the Company’s revolving credit facility. During the quarter ended June 30, 2020, the Company purchased in the open market and canceled senior notes issued under its indentures in an aggregate principal amount of $410 million for an aggregate purchase price of $267 million in cash, including accrued interest and broker fees, reflecting a discount to par of an aggregate $147 million . These repurchases resulted in a $140 million net gain on extinguishment of debt. The net gain includes an acceleration of related discount and debt issuance costs. The repurchases were financed by borrowings under the Company’s revolving credit facility. The Company records gains and losses on extinguishment of debt in “Financing costs, net” in the Company’s statement of consolidated operations. In March 2018, the Company entered into a revolving credit facility with commitments totaling $4.0 billion . In March 2019, the term of this facility was extended by one year to March 2024 (subject to Apache’s remaining one-year extension option) pursuant to Apache’s exercise of an extension option. The Company can increase commitments up to $5.0 billion by adding new lenders or obtaining the consent of any increasing existing lenders. The facility includes a letter of credit subfacility of up to $3.0 billion, of which $2.08 billion was committed as of September 30, 2020 . The facility is for general corporate purposes, and available committed borrowing capacity supports Apache’s commercial paper program. As of September 30, 2020 , there were $87 million of borrowings and an aggregate £637 million in letters of credit outstanding under this facility. As of December 31, 2019 , there were no borrowings or letters of credit outstanding under this facility. The outstanding letters of credit were issued to support North Sea decommissioning obligations, the terms of which required such support after Standard & Poor’s reduced the Company’s credit rating from BBB to BB+ on March 26, 2020. The Company’s $3.5 billion commercial paper program, which is subject to market availability, facilitates Apache borrowing funds for up to 270 days . As a result of downgrades in Apache’s credit ratings during 2020, the Company does not expect that its commercial paper program will be cost competitive with its other financing alternatives and does not anticipate using it under such circumstances. As of September 30, 2020 and December 31, 2019 , the Company had no commercial paper outstanding. In November 2018, Altus Midstream LP entered into a revolving credit facility for general corporate purposes that matures in November 2023 (subject to Altus Midstream LP’s two , one-year extension options). The agreement for this facility, as amended, provides aggregate commitments from a syndicate of banks of $800 million . All aggregate commitments include a letter of credit subfacility of up to $100 million and a swingline loan subfacility of up to $100 million . Altus Midstream LP may increase commitments up to an aggregate $1.5 billion by adding new lenders or obtaining the consent of any increasing existing lenders. As of September 30, 2020 and December 31, 2019 , there were $580 million and $396 million , respectively, of borrowings outstanding under this facility. As of September 30, 2020 and December 31, 2019 , there were no letters of credit outstanding under this facility. The Altus Midstream LP credit facility is unsecured and is not guaranteed by Apache or any of Apache’s other subsidiaries. Financing Costs, Net The following table presents the components of Apache’s financing costs, net: For the Quarter Ended September 30, For the Nine Months Ended September 30, 2020 2019 2020 2019 (In millions) Interest expense $ 113 $ 107 $ 327 $ 323 Amortization of debt issuance costs 2 2 6 5 Capitalized interest (3 ) (9 ) (9 ) (26 ) Loss (gain) on extinguishment of debt (12 ) — (152 ) 75 Interest income (1 ) (5 ) (4 ) (12 ) Financing costs, net $ 99 $ 95 $ 168 $ 365

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	9 Months Ended
	Sep. 30, 2020
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES Legal Matters Apache is party to various legal actions arising in the ordinary course of business, including litigation and governmental and regulatory controls. As of September 30, 2020 , the Company has an accrued liability of approximately $69 million for all legal contingencies that are deemed to be probable of occurring and can be reasonably estimated. Apache’s estimates are based on information known about the matters and its experience in contesting, litigating, and settling similar matters. Although actual amounts could differ from management’s estimate, none of the actions are believed by management to involve future amounts that would be material to Apache’s financial position, results of operations, or liquidity after consideration of recorded accruals. For material matters that Apache believes an unfavorable outcome is reasonably possible, the Company has disclosed the nature of the matter and a range of potential exposure, unless an estimate cannot be made at this time. It is management’s opinion that the loss for any other litigation matters and claims that are reasonably possible to occur will not have a material adverse effect on the Company’s financial position, results of operations, or liquidity. For additional information on Legal Matters described below, please see Note 11—Commitments and Contingencies to the consolidated financial statements contained in Apache’s Annual Report on Form 10-K for the fiscal year ended December 31, 2019 . Argentine Environmental Claims and Argentina Tariff No material change in the status of the YPF Sociedad Anónima and Pioneer Natural Resources Company indemnities matter has occurred since the filing of Apache’s Annual Report on Form 10-K for the fiscal year ended December 31, 2019 . Louisiana Restoration As more fully described in Apache’s Annual Report on Form 10-K for the fiscal year ended December 31, 2019 , Louisiana surface owners often file lawsuits or assert claims against oil and gas companies, including Apache, claiming that operators and working interest owners in the chain of title are liable for environmental damages on the leased premises, including damages measured by the cost of restoration of the leased premises to its original condition, regardless of the value of the underlying property. From time to time, restoration lawsuits and claims are resolved by the Company for amounts that are not material to the Company, while new lawsuits and claims are asserted against the Company. With respect to each of the pending lawsuits and claims, the amount claimed is not currently determinable or is not material. Further, the overall exposure related to these lawsuits and claims is not currently determinable. While adverse judgments against the Company are possible, the Company intends to actively defend these lawsuits and claims. Starting in November of 2013 and continuing into 2020, several parishes in Louisiana have pending lawsuits against many oil and gas producers, including Apache. These cases were all removed to federal courts in Louisiana. Some of the cases have been remanded to state court with the remand orders being appealed. In these cases, the Parishes, as plaintiffs, allege that defendants’ oil and gas exploration, production, and transportation operations in specified fields were conducted in violation of the State and Local Coastal Resources Management Act of 1978, as amended, and applicable regulations, rules, orders, and ordinances promulgated or adopted thereunder by the Parish or the State of Louisiana. Plaintiffs allege that defendants caused substantial damage to land and water bodies located in the coastal zone of Louisiana. Plaintiffs seek, among other things, unspecified damages for alleged violations of applicable law within the coastal zone, the payment of costs necessary to clear, re-vegetate, detoxify, and otherwise restore the subject coastal zone as near as practicable to its original condition, and actual restoration of the coastal zone to its original condition. While adverse judgments against the Company might be possible, the Company intends to vigorously oppose these claims. No other material change in the status of these matters has occurred since the filing of Apache’s Annual Report on Form 10-K for the fiscal year ended December 31, 2019 . Apollo Exploration Lawsuit In a case captioned Apollo Exploration, LLC, Cogent Exploration, Ltd. Co. & SellmoCo, LLC v. Apache Corporation , Cause No. CV50538 in the 385 th Judicial District Court, Midland County, Texas, plaintiffs alleged damages in excess of $200 million (having previously claimed in excess of $1.1 billion ) relating to purchase and sale agreements, mineral leases, and areas of mutual interest agreements concerning properties located in Hartley, Moore, Potter, and Oldham Counties, Texas. The Court entered final judgment in favor of the Company, ruling that the plaintiffs take nothing by their claims and awarding the Company its attorneys’ fees and costs incurred in defending the lawsuit. The plaintiffs have appealed. No other material change in the status of this matter has occurred since the filing of Apache’s Annual Report on Form 10-K for the fiscal year ended December 31, 2019 . Australian Operations Divestiture Dispute Pursuant to a Sale and Purchase Agreement dated April 9, 2015 (Quadrant SPA), the Company and its subsidiaries divested their remaining Australian operations to Quadrant Energy Pty Ltd (Quadrant). Closing occurred on June 5, 2015. In April 2017, Apache filed suit against Quadrant for breach of the Quadrant SPA. In its suit, Apache seeks approximately AUD $80 million . In December 2017, Quadrant filed a defense of equitable set-off to Apache’s claim and a counterclaim seeking approximately AUD $200 million in the aggregate. The Company believes that Quadrant’s claims lack merit and will not have a material adverse effect on the Company’s financial position, results of operation, or liquidity. Canadian Operations Divestiture Dispute Pursuant to a Sale and Purchase Agreement dated July 6, 2017 (Paramount SPA), the Company and its subsidiaries divested their remaining Canadian operations to Paramount Resources LTD (Paramount). Closing occurred on August 16, 2017. On September 11, 2019, four ex-employees of Apache Canada on behalf of themselves and individuals employed by Apache Canada LTD on July 6, 2017, filed an Amended Statement of Claim in a matter styled Stephen Flesch et. al. v Apache Corporation et. al ., No. 1901-09160 Court of Queen’s Bench of Alberta against the Company and others seeking class certification and a finding that the Paramount SPA amounted to a Change of Control of the Company, entitling them to accelerated vesting under the Company’s equity plans. In the suit, the purported class seeks approximately $60 million USD and punitive damages. The Company believes that Plaintiffs’ claims lack merit and will not have a material adverse effect on the Company’s financial position, results of operation, or liquidity. California and Delaware Litigation On July 17, 2017, in three separate actions, San Mateo County, California, Marin County, California, and the City of Imperial Beach, California, all filed suit individually and on behalf of the people of the state of California against over 30 oil and gas companies alleging damages as a result of global warming. Plaintiffs seek unspecified damages and abatement under various tort theories. On December 20, 2017, in two separate actions, the City of Santa Cruz and Santa Cruz County and in a separate action on January 22, 2018, the City of Richmond, filed similar lawsuits against many of the same defendants. On November 14, 2018, the Pacific Coast Federation of Fishermen’s Associations, Inc. also filed a similar lawsuit against many of the same defendants. After removal of all such lawsuits to federal court, the district court remanded them back to state court. The remand decision, and further activity in the cases, has been stayed pending further appellate review. On September 10, 2020, the state of Delaware filed suit, individually and on behalf of the people of the state of Delaware, against over 25 oil and gas companies alleging damages as a result of global warming. Plaintiffs seek unspecified damages and abatement under various tort theories. The Company believes that the claims made against it in the California and Delaware litigation are baseless and intends to vigorously defend these lawsuits. Castex Lawsuit In a case styled Apache Corporation v. Castex Offshore, Inc, et. al. , Cause No. 2015-48580, in the 113th Judicial District Court of Harris County, Texas, Castex filed claims for alleged damages of approximately $200 million , relating to overspend on the Belle Isle Gas Facility upgrade, and the drilling of five sidetracks on the Potomac #3 well. After a jury trial, a verdict of approximately $60 million , plus fees, costs, and interest was entered against the Company. The Company is appealing. Oklahoma Class Actions Apache is a party to two purported class actions in Oklahoma styled Bigie Lee Rhea v. Apache Corporation , Case No. 6:14-cv-00433-JH, and Albert Steven Allen v. Apache Corporation , Case No. CJ-2019-00219. The Rhea case has been certified, and Apache’s appeal of the certification was recently denied. The case includes a class of royalty owners seeking damages in excess of $250 million for alleged breach of the implied covenant to market relating to post-production deductions and alleged NGL uplift value. The Allen case has not been certified and seeks to represent a group of owners who have allegedly received late royalty payments under Oklahoma statutes. The amount of this claim is not yet reasonably determinable. While adverse judgments against the Company are possible, the Company intends to vigorously defend these lawsuits and claims. Environmental Matters As of September 30, 2020 , the Company had an undiscounted reserve for environmental remediation of approximately $2 million . On September 11, 2020, Apache received a Notice of Violation and Finding of Violation, and accompanying Clean Air Act Information Request, from the U.S. Environmental Protection Agency (EPA) following site inspections in April 2019 at several of Apache’s oil and natural gas production facilities in Lea and Eddy Counties, New Mexico. The Notice and Information Request involve alleged emissions control and reporting violations. Apache is cooperating with the EPA and responding to its information requests. The EPA has not commenced enforcement proceedings, and at this time the Company is unable to reasonably estimate whether such proceedings will result in monetary sanctions and, if so, whether they would be more or less than $100,000 , exclusive of interest and costs. The Company is not aware of any environmental claims existing as of September 30, 2020 that have not been provided for or would otherwise have a material impact on its financial position, results of operations, or liquidity. There can be no assurance, however, that current regulatory requirements will not change or past non-compliance with environmental laws will not be discovered on the Company’s properties. Potential Asset Retirement Obligations In 2013, Apache sold its Gulf of Mexico Shelf operations and properties (Transferred Assets) to Fieldwood Energy LLC (Fieldwood). Under the terms of the purchase agreement (Agreement), Apache received cash consideration of $3.75 billion and Fieldwood assumed $1.5 billion of discounted asset abandonment liabilities. In respect of such abandonment liabilities, Fieldwood posted letters of credit in favor of Apache (Letters of Credit) and established a trust account (Trust A), which is funded by a 10 percent net profits interest depending on future oil prices and of which Apache is the beneficiary. On February 14, 2018, Fieldwood filed for protection under Chapter 11 of the U.S. Bankruptcy Code. In connection with the 2018 bankruptcy, Fieldwood confirmed a plan under which Apache agreed, inter alia, to accept bonds in exchange for certain of the Letters of Credit. Currently, Apache holds two bonds (Bonds) and the remaining Letters of Credit to secure Fieldwood’s asset retirement obligations (AROs) on the Transferred Assets as and when such abandonment and decommissioning obligations are required to be performed over the remaining life of the Transferred Assets. On August 3, 2020, Fieldwood filed for protection under Chapter 11 of the U.S. Bankruptcy Code. Apache has been engaged with Fieldwood and other interested parties to discuss Fieldwood’s plan of reorganization. However, as of the date of this report, Apache does not know if, or to what extent, Fieldwood will be able to continue to perform its AROs with respect to the Transferred Assets. If Fieldwood fails to perform any of its AROs with respect to the Transferred Assets, then Apache’s remedy would be a claim for damages against Fieldwood for breach of its contractual obligations under the Agreement. If Fieldwood fails to perform any of its AROs on the Transferred Assets, then Apache would expect the relevant governmental authorities to require Apache to perform, and hold Apache financially responsible for, such AROs to the extent not performed by Fieldwood. Pending resolution of any claim by Apache for breach of the Agreement, Apache may be forced to use available cash to cover the costs it incurs for performing such AROs. While Apache anticipates that all, or a portion, of such costs would be reimbursable to Apache under the remaining Letters of Credit, the Bonds and Trust A, it is possible that such decommissioning security may not be sufficient to cover all of the costs and expenses incurred by Apache in performing such AROs or such decommissioning security may be reduced, restricted, or otherwise eliminated, in whole or in part, as a result of Fieldwood’s current bankruptcy proceedings.

REDEMABLE NONCONTROLLING INTERE

REDEMABLE NONCONTROLLING INTEREST - ALTUS	9 Months Ended
	Sep. 30, 2020
Equity [Abstract]
REDEMABLE NONCONTROLLING INTEREST - ALTUS	REDEEMABLE NONCONTROLLING INTEREST - ALTUS Preferred Units Issuance On June 12, 2019, Altus Midstream LP issued and sold Preferred Units for an aggregate issue price of $625 million in a private offering exempt from the registration requirements of the Securities Act of 1933, as amended (the Closing). Altus Midstream LP received approximately $611 million in cash proceeds from the sale after deducting transaction costs and discounts to certain purchasers. Classification The Preferred Units are accounted for on the Company’s consolidated balance sheets as a redeemable noncontrolling interest classified as temporary equity based on the terms of the Preferred Units, including the redemption rights with respect thereto. Initial Measurement Altus recorded the net transaction price of $611 million , calculated as the negotiated transaction price of $625 million , less issue discounts of $4 million and transaction costs totaling $10 million . Certain redemption features embedded within the terms of the Preferred Units require bifurcation and measurement at fair value. Altus bifurcated and recognized at fair value an embedded derivative related to the Preferred Units at inception of $94 million for a redemption option of the Preferred Unit holders. The derivative is reflected in “Other” within “Deferred Credits and Other Noncurrent Liabilities” on the Company’s consolidated balance sheet at its current fair value of $179 million . The fair value of the embedded derivative, a Level 3 fair value measurement, was based on numerous factors including expected future interest rates using the Black-Karasinski model, Altus’ imputed interest rate, the timing of periodic cash distributions, and dividend yields of the Preferred Units. See Note 4—Derivative Instruments and Hedging Activities for more detail. The net transaction price was allocated to the preferred redeemable noncontrolling interest and the embedded features according to the associated initial fair value measurements as follows: June 12, 2019 (In millions) Redeemable noncontrolling interest - Altus Preferred Unit limited partners $ 517 Preferred Units embedded derivative 94 $ 611 Subsequent Measurement Altus applies a two-step approach to subsequent measurement of the redeemable noncontrolling interest related to the Preferred Units by first allocating a portion of the net income of Altus Midstream LP in accordance with the terms of the partnership agreement. An additional adjustment to the carrying value of the Preferred Unit redeemable noncontrolling interest at each period end may be recorded, if applicable. The amount of such adjustment is determined based upon the accreted value method to reflect the passage of time until the Preferred Units are exchangeable at the option of the holder. Pursuant to this method, the net transaction price is accreted using the effective interest method to the Redemption Price calculated at the seventh anniversary of the Closing. The total adjustment is limited to an amount such that the carrying amount of the Preferred Unit redeemable noncontrolling interest at each period end is equal to the greater of (a) the sum of (i) the carrying amount of the Preferred Units, plus (ii) the fair value of the embedded derivative liability and (b) the accreted value of the net transaction price. Activity related to the Preferred Units during the nine months ended September 30, 2020 is as follows: Units Outstanding Financial Position (1) (In millions, except unit data) Redeemable noncontrolling interest - Altus Preferred Unit limited partners: at December 31, 2019 638,163 $ 555 Distribution of in-kind additional Preferred Units 22,531 — Cash distributions to Altus Preferred Unit limited partners — (11 ) Allocation of Altus Midstream LP net income N/A 56 Redeemable noncontrolling interest - Altus Preferred Unit limited partners: at September 30, 2020 660,694 600 Preferred Units embedded derivative 179 $ 779 (1) The Preferred Units are redeemable at Altus Midstream LP’s option at September 30, 2020 at a price (the Redemption Price) equal to (a) the greater of (i) an 11.5 percent internal rate of return and (ii) a 1.3 times multiple of invested capital. As of September 30, 2020 , the greater of these two amounts was a 1.3 times multiple of invested capital which equaled $813 million . As of September 30, 2020 , the aggregate Redemption Price using an 11.5 percent internal rate of return was $709 million . N/A - not applicable. CAPITAL STOCK Net Loss per Common Share A reconciliation of the components of basic and diluted net loss per common share for the periods presented in the consolidated financial statements is shown in the tables below. For the Quarter Ended September 30, 2020 2019 Loss Shares Per Share Loss Shares Per Share (In millions, except per share amounts) Basic: Loss attributable to common stock $ (4 ) 378 $ (0.01 ) $ (170 ) 377 $ (0.45 ) Effect of Dilutive Securities: Stock options and other $ — — $ — $ — — $ — Redeemable noncontrolling interest - Altus Preferred Unit limited partners $ (4 ) — $ (0.01 ) $ — — $ — Diluted: Loss attributable to common stock $ (8 ) 378 $ (0.02 ) $ (170 ) 377 $ (0.45 ) For the Nine Months Ended September 30, 2020 2019 Loss Shares Per Share Loss Shares Per Share (In millions, except per share amounts) Basic: Loss attributable to common stock $ (4,870 ) 378 $ (12.89 ) $ (577 ) 377 $ (1.53 ) Effect of Dilutive Securities: Stock options and other $ — — $ — $ — — $ — Diluted: Loss attributable to common stock $ (4,870 ) 378 $ (12.89 ) $ (577 ) 377 $ (1.53 ) The Company uses the “if-converted method” to determine the potential dilutive effect of an assumed exchange of the outstanding Preferred Units of Altus Midstream for shares of Altus’ common stock. The impact to net loss attributable to common stock on an assumed conversion of the Preferred Units was anti-dilutive for the quarter ended September 30, 2019 and for each of the nine months ended September 30, 2020 and 2019 . The diluted earnings per share calculation excludes options and restricted stock units that were anti-dilutive totaling 4.2 million and 5.2 million for the quarters ended September 30, 2020 and 2019 , respectively, and 5.1 million for each of the nine months ended September 30, 2020 and 2019 . Common Stock Dividends For the quarters ended September 30, 2020 and 2019 , Apache paid $9 million and $94 million , respectively, in dividends on its common stock. For the nine months ended September 30, 2020 and 2019, Apache paid $113 million and $282 million , respectively. In the first quarter of 2020, Apache’s Board of Directors approved a reduction in the Company’s quarterly dividend per share from $0.25 to $0.025 , effective for all dividends payable after March 12, 2020. Stock Repurchase Program In 2013 and 2014, Apache’s Board of Directors authorized the purchase of up to 40 million shares of the Company’s common stock. Shares may be purchased either in the open market or through privately held negotiated transactions. The Company initiated the buyback program on June 10, 2013, and through September 30, 2020 , had repurchased a total of 40 million shares at an average price of $79.18 per share. During the fourth quarter of 2018, the Company’s Board of Directors authorized the purchase of up to 40 million additional shares of the Company’s common stock. The Company is not obligated to acquire any specific number of shares and did no t purchase any shares during the nine months ended September 30, 2020 .

CAPITAL STOCK

CAPITAL STOCK	9 Months Ended
	Sep. 30, 2020
Equity [Abstract]
CAPITAL STOCK	REDEEMABLE NONCONTROLLING INTEREST - ALTUS Preferred Units Issuance On June 12, 2019, Altus Midstream LP issued and sold Preferred Units for an aggregate issue price of $625 million in a private offering exempt from the registration requirements of the Securities Act of 1933, as amended (the Closing). Altus Midstream LP received approximately $611 million in cash proceeds from the sale after deducting transaction costs and discounts to certain purchasers. Classification The Preferred Units are accounted for on the Company’s consolidated balance sheets as a redeemable noncontrolling interest classified as temporary equity based on the terms of the Preferred Units, including the redemption rights with respect thereto. Initial Measurement Altus recorded the net transaction price of $611 million , calculated as the negotiated transaction price of $625 million , less issue discounts of $4 million and transaction costs totaling $10 million . Certain redemption features embedded within the terms of the Preferred Units require bifurcation and measurement at fair value. Altus bifurcated and recognized at fair value an embedded derivative related to the Preferred Units at inception of $94 million for a redemption option of the Preferred Unit holders. The derivative is reflected in “Other” within “Deferred Credits and Other Noncurrent Liabilities” on the Company’s consolidated balance sheet at its current fair value of $179 million . The fair value of the embedded derivative, a Level 3 fair value measurement, was based on numerous factors including expected future interest rates using the Black-Karasinski model, Altus’ imputed interest rate, the timing of periodic cash distributions, and dividend yields of the Preferred Units. See Note 4—Derivative Instruments and Hedging Activities for more detail. The net transaction price was allocated to the preferred redeemable noncontrolling interest and the embedded features according to the associated initial fair value measurements as follows: June 12, 2019 (In millions) Redeemable noncontrolling interest - Altus Preferred Unit limited partners $ 517 Preferred Units embedded derivative 94 $ 611 Subsequent Measurement Altus applies a two-step approach to subsequent measurement of the redeemable noncontrolling interest related to the Preferred Units by first allocating a portion of the net income of Altus Midstream LP in accordance with the terms of the partnership agreement. An additional adjustment to the carrying value of the Preferred Unit redeemable noncontrolling interest at each period end may be recorded, if applicable. The amount of such adjustment is determined based upon the accreted value method to reflect the passage of time until the Preferred Units are exchangeable at the option of the holder. Pursuant to this method, the net transaction price is accreted using the effective interest method to the Redemption Price calculated at the seventh anniversary of the Closing. The total adjustment is limited to an amount such that the carrying amount of the Preferred Unit redeemable noncontrolling interest at each period end is equal to the greater of (a) the sum of (i) the carrying amount of the Preferred Units, plus (ii) the fair value of the embedded derivative liability and (b) the accreted value of the net transaction price. Activity related to the Preferred Units during the nine months ended September 30, 2020 is as follows: Units Outstanding Financial Position (1) (In millions, except unit data) Redeemable noncontrolling interest - Altus Preferred Unit limited partners: at December 31, 2019 638,163 $ 555 Distribution of in-kind additional Preferred Units 22,531 — Cash distributions to Altus Preferred Unit limited partners — (11 ) Allocation of Altus Midstream LP net income N/A 56 Redeemable noncontrolling interest - Altus Preferred Unit limited partners: at September 30, 2020 660,694 600 Preferred Units embedded derivative 179 $ 779 (1) The Preferred Units are redeemable at Altus Midstream LP’s option at September 30, 2020 at a price (the Redemption Price) equal to (a) the greater of (i) an 11.5 percent internal rate of return and (ii) a 1.3 times multiple of invested capital. As of September 30, 2020 , the greater of these two amounts was a 1.3 times multiple of invested capital which equaled $813 million . As of September 30, 2020 , the aggregate Redemption Price using an 11.5 percent internal rate of return was $709 million . N/A - not applicable. CAPITAL STOCK Net Loss per Common Share A reconciliation of the components of basic and diluted net loss per common share for the periods presented in the consolidated financial statements is shown in the tables below. For the Quarter Ended September 30, 2020 2019 Loss Shares Per Share Loss Shares Per Share (In millions, except per share amounts) Basic: Loss attributable to common stock $ (4 ) 378 $ (0.01 ) $ (170 ) 377 $ (0.45 ) Effect of Dilutive Securities: Stock options and other $ — — $ — $ — — $ — Redeemable noncontrolling interest - Altus Preferred Unit limited partners $ (4 ) — $ (0.01 ) $ — — $ — Diluted: Loss attributable to common stock $ (8 ) 378 $ (0.02 ) $ (170 ) 377 $ (0.45 ) For the Nine Months Ended September 30, 2020 2019 Loss Shares Per Share Loss Shares Per Share (In millions, except per share amounts) Basic: Loss attributable to common stock $ (4,870 ) 378 $ (12.89 ) $ (577 ) 377 $ (1.53 ) Effect of Dilutive Securities: Stock options and other $ — — $ — $ — — $ — Diluted: Loss attributable to common stock $ (4,870 ) 378 $ (12.89 ) $ (577 ) 377 $ (1.53 ) The Company uses the “if-converted method” to determine the potential dilutive effect of an assumed exchange of the outstanding Preferred Units of Altus Midstream for shares of Altus’ common stock. The impact to net loss attributable to common stock on an assumed conversion of the Preferred Units was anti-dilutive for the quarter ended September 30, 2019 and for each of the nine months ended September 30, 2020 and 2019 . The diluted earnings per share calculation excludes options and restricted stock units that were anti-dilutive totaling 4.2 million and 5.2 million for the quarters ended September 30, 2020 and 2019 , respectively, and 5.1 million for each of the nine months ended September 30, 2020 and 2019 . Common Stock Dividends For the quarters ended September 30, 2020 and 2019 , Apache paid $9 million and $94 million , respectively, in dividends on its common stock. For the nine months ended September 30, 2020 and 2019, Apache paid $113 million and $282 million , respectively. In the first quarter of 2020, Apache’s Board of Directors approved a reduction in the Company’s quarterly dividend per share from $0.25 to $0.025 , effective for all dividends payable after March 12, 2020. Stock Repurchase Program In 2013 and 2014, Apache’s Board of Directors authorized the purchase of up to 40 million shares of the Company’s common stock. Shares may be purchased either in the open market or through privately held negotiated transactions. The Company initiated the buyback program on June 10, 2013, and through September 30, 2020 , had repurchased a total of 40 million shares at an average price of $79.18 per share. During the fourth quarter of 2018, the Company’s Board of Directors authorized the purchase of up to 40 million additional shares of the Company’s common stock. The Company is not obligated to acquire any specific number of shares and did no t purchase any shares during the nine months ended September 30, 2020 .

BUSINESS SEGMENT INFORMATION

BUSINESS SEGMENT INFORMATION	9 Months Ended
	Sep. 30, 2020
Segment Reporting [Abstract]
BUSINESS SEGMENT INFORMATION	BUSINESS SEGMENT INFORMATION As of September 30, 2020 , Apache is engaged in exploration and production (Upstream) activities across three operating segments: Egypt, North Sea, and the U.S. Apache also has exploration interests in Suriname and other international locations that may, over time, result in reportable discoveries and development opportunities. Apache’s Upstream business explores for, develops, and produces natural gas, crude oil, and natural gas liquids. Apache’s midstream business is operated by Altus, which owns, develops, and operates a midstream energy asset network in the Permian Basin of West Texas, anchored by midstream service contracts to Apache’s production from its Alpine High resource play. Financial information for each segment is presented below: Egypt (1) North Sea U.S. Altus Intersegment Eliminations & Other Total (2) Upstream Midstream (In millions) For the Quarter Ended September 30, 2020 Revenues: Oil revenues $ 303 $ 179 $ 303 $ — $ — $ 785 Natural gas revenues 74 13 77 — — 164 Natural gas liquids revenues 2 5 90 — — 97 Oil, natural gas, and natural gas liquids production revenues 379 197 470 — — 1,046 Purchased oil and gas sales — — 73 1 — 74 Midstream service affiliate revenues — — — 39 (39 ) — 379 197 543 40 (39 ) 1,120 Operating Expenses: Lease operating expenses 102 79 79 — (1 ) 259 Gathering, processing, and transmission 8 10 74 9 (38 ) 63 Purchased oil and gas costs — — 74 1 — 75 Taxes other than income — — 30 4 — 34 Exploration 10 10 34 — 4 58 Depreciation, depletion, and amortization 144 90 161 3 — 398 Asset retirement obligation accretion — 18 8 1 — 27 264 207 460 18 (35 ) 914 Operating Income (Loss) (3) $ 115 $ (10 ) $ 83 $ 22 $ (4 ) 206 Other Income (Expense): Derivative instrument gains, net 16 Loss on divestitures, net (1 ) Other, net 9 General and administrative (52 ) Transaction, reorganization, and separation (7 ) Financing costs, net (99 ) Income Before Income Taxes $ 72 Egypt (1) North Sea U.S. Altus Intersegment Eliminations & Other Total (2) Upstream Midstream (In millions) For the Nine Months Ended September 30, 2020 Revenues: Oil revenues $ 823 $ 578 $ 929 $ — $ — $ 2,330 Natural gas revenues 209 39 169 — — 417 Natural gas liquids revenues 6 15 211 — — 232 Oil, natural gas, and natural gas liquids production revenues 1,038 632 1,309 — — 2,979 Purchased oil and gas sales — — 235 2 — 237 Midstream service affiliate revenues — — — 111 (111 ) — 1,038 632 1,544 113 (111 ) 3,216 Operating Expenses: Lease operating expenses 312 234 313 — (1 ) 858 Gathering, processing, and transmission 31 37 219 29 (110 ) 206 Purchased oil and gas costs — — 205 2 — 207 Taxes other than income — — 79 11 — 90 Exploration 51 26 100 — 10 187 Depreciation, depletion, and amortization 463 278 632 9 — 1,382 Asset retirement obligation accretion — 54 24 3 — 81 Impairments 529 7 3,956 — — 4,492 1,386 636 5,528 54 (101 ) 7,503 Operating Income (Loss) (3) $ (348 ) $ (4 ) $ (3,984 ) $ 59 $ (10 ) (4,287 ) Other Income (Expense): Derivative instrument losses, net (262 ) Gain on divestitures 24 Other 41 General and administrative (214 ) Transaction, reorganization, and separation (44 ) Financing costs, net (168 ) Loss Before Income Taxes $ (4,910 ) Total Assets (4) $ 3,052 $ 2,238 $ 5,708 $ 1,741 $ 136 $ 12,875 Egypt (1) North Sea U.S. Altus Intersegment Eliminations & Other Total (2) Upstream Midstream (In millions) For the Quarter Ended September 30, 2019 Revenues: Oil revenues $ 472 $ 231 $ 504 $ — $ — $ 1,207 Natural gas revenues 72 14 50 — — 136 Natural gas liquids revenues 2 5 88 — — 95 Oil, natural gas, and natural gas liquids production revenues 546 250 642 — — 1,438 Purchased oil and gas sales — — 30 — — 30 Midstream service affiliate revenues — — — 34 (34 ) — 546 250 672 34 (34 ) 1,468 Operating Expenses: Lease operating expenses 115 76 159 — — 350 Gathering, processing, and transmission 9 9 69 13 (34 ) 66 Purchased oil and gas costs — — 23 — — 23 Taxes other than income — — 41 3 — 44 Exploration 27 — 25 — 4 56 Depreciation, depletion, and amortization 177 71 452 11 — 711 Asset retirement obligation accretion — 19 8 — — 27 Impairments — — — 9 — 9 328 175 777 36 (30 ) 1,286 Operating Income (Loss) (3) $ 218 $ 75 $ (105 ) $ (2 ) $ (4 ) 182 Other Income (Expense): Derivative instrument losses, net (2 ) Other 34 General and administrative (98 ) Transaction, reorganization, and separation (7 ) Financing costs, net (95 ) Income Before Income Taxes $ 14 Egypt (1) North Sea U.S. Altus Intersegment Eliminations & Other Total (2) Upstream Midstream (In millions) For the Nine Months Ended September 30, 2019 Revenues: Oil revenues $ 1,509 $ 868 $ 1,537 $ — $ — $ 3,914 Natural gas revenues 223 64 203 — — 490 Natural gas liquids revenues 9 16 261 — — 286 Oil, natural gas, and natural gas liquids production revenues 1,741 948 2,001 — — 4,690 Purchased oil and gas sales — — 72 — — 72 Midstream service affiliate revenues — — — 92 (92 ) — 1,741 948 2,073 92 (92 ) 4,762 Operating Expenses: Lease operating expenses 365 240 501 — (2 ) 1,104 Gathering, processing, and transmission 31 32 214 43 (90 ) 230 Purchased oil and gas costs — — 60 — — 60 Taxes other than income — — 131 10 — 141 Exploration 89 2 117 — 12 220 Depreciation, depletion, and amortization 538 269 1,125 27 — 1,959 Asset retirement obligation accretion — 56 23 1 — 80 Impairments — — 240 9 — 249 1,023 599 2,411 90 (80 ) 4,043 Operating Income (Loss) (3) $ 718 $ 349 $ (338 ) $ 2 $ (12 ) 719 Other Income (Expense): Derivative instrument losses, net (40 ) Gain on divestitures, net 20 Other, net 33 General and administrative (323 ) Transaction, reorganization, and separation (17 ) Financing costs, net (365 ) Income Before Income Taxes $ 27 Total Assets (4) $ 3,851 $ 2,529 $ 12,289 $ 2,648 $ 88 $ 21,405 (1) Includes revenue from non-customers of: For the Quarter Ended September 30, For the Nine Months Ended September 30, 2020 2019 2020 2019 (In millions) Oil $ 38 $ 98 $ 65 $ 316 Natural gas 6 9 9 30 Natural gas liquids — — — 1 (2) Includes a noncontrolling interest in Egypt and Altus. (3) The operating income of U.S. and Egypt includes leasehold and other asset impairments totaling $34 million and $2 million , respectively, for the third quarter of 2020 . The operating loss of U.S., Egypt, and North Sea includes leasehold and other asset impairments totaling $4.0 billion , $535 million , and $7 million , respectively, for the first nine months of 2020. The operating income (loss) of U.S., Altus Midstream, and Egypt includes leasehold and other asset impairments totaling $10 million , $9 million and $2 million , respectively, for the third quarter of 2019 . The operating income (loss) of U.S., Altus Midstream, and Egypt includes leasehold and other asset impairments totaling $308 million , $9 million , and $6 million , respectively, for the first nine months of 2019 . (4) Intercompany balances are excluded from total assets.

SUMMARY OF SIGNIFICANT ACCOUN_2

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	9 Months Ended
	Sep. 30, 2020
Accounting Policies [Abstract]
Principles of Consolidation	The accompanying consolidated financial statements include the accounts of Apache and its subsidiaries after elimination of intercompany balances and transactions. The Company’s undivided interests in oil and gas exploration and production ventures and partnerships are proportionately consolidated. The Company consolidates all other investments in which, either through direct or indirect ownership, Apache has more than a 50 percent voting interest or controls the financial and operating decisions. Noncontrolling interests represent third-party ownership in the net assets of a consolidated Apache subsidiary and are reflected separately in the Company’s financial statements. Sinopec International Petroleum Exploration and Production Corporation (Sinopec) owns a one-third minority participation in Apache’s Egypt oil and gas business as a noncontrolling interest, which is reflected as a separate component of equity in Apache’s consolidated balance sheet. Additionally, third-party investors own a minority interest of approximately 21 percent of Altus Midstream Company (ALTM), which is reflected as a separate noncontrolling interest component of equity in Apache’s consolidated balance sheet. ALTM qualifies as a variable interest entity (VIE) under GAAP. Apache consolidates the activities of ALTM because it has concluded that it has a controlling financial interest in ALTM and is the primary beneficiary of the VIE. On June 12, 2019, Altus Midstream LP issued and sold Series A Cumulative Redeemable Preferred Units (the Preferred Units) through a private offering that admitted additional limited partners with separate rights for the Preferred Unit holders. Refer to Note 12—Redeemable Noncontrolling Interest - Altus for more detail. Investments in which Apache holds less than 50 percent
Use of Estimates	Preparation of financial statements in conformity with GAAP and disclosure of contingent assets and liabilities requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. The Company bases its estimates on historical experience and various other assumptions that are believed to be reasonable under the circumstances, the results of which form the basis for making judgments about carrying values of assets and liabilities that are not readily apparent from other sources. Apache evaluates its estimates and assumptions on a regular basis. Actual results may differ from these estimates and assumptions used in preparation of its financial statements and changes in these estimates are recorded when known. Significant estimates with regard to these financial statements include the estimate of proved oil and gas reserves and related present value estimates of future net cash flows therefrom, the assessment of asset retirement obligations (see Note 8—Asset Retirement Obligation ), the estimates of fair value for long-lived assets (see “Fair Value Measurements,” “Oil and Gas Property,” and “Gathering, Processing, and Transmission Facilities” sections in this Note 1 below), and the estimate of income taxes (see Note 9—Income Taxes ). Actual results could differ from those estimates.
Fair Value Measurements	Certain assets and liabilities are reported at fair value on a recurring basis in Apache’s consolidated balance sheet. Accounting Standards Codification (ASC) 820-10-35, “Fair Value Measurement” (ASC 820), provides a hierarchy that prioritizes and defines the types of inputs used to measure fair value. The fair value hierarchy gives the highest priority to Level 1 inputs, which consist of unadjusted quoted prices for identical instruments in active markets. Level 2 inputs consist of quoted prices for similar instruments. Level 3 valuations are derived from inputs that are significant and unobservable; hence, these valuations have the lowest priority.
Oil and Gas Property	The Company follows the successful efforts method of accounting for its oil and gas property. Under this method of accounting, exploration costs, such as exploratory geological and geophysical costs, delay rentals, and exploration overhead, are expensed as incurred. All costs related to production, general corporate overhead, and similar activities are expensed as incurred. If an exploratory well provides evidence to justify potential development of reserves, drilling costs associated with the well are initially capitalized, or suspended, pending a determination as to whether a commercially sufficient quantity of proved reserves can be attributed to the area as a result of drilling. This determination may take longer than one year in certain areas depending on, among other things, the amount of hydrocarbons discovered, the outcome of planned geological and engineering studies, the need for additional appraisal drilling activities to determine whether the discovery is sufficient to support an economic development plan, and government sanctioning of development activities in certain international locations. At the end of each quarter, management reviews the status of all suspended exploratory well costs in light of ongoing exploration activities; in particular, whether the Company is making sufficient progress in its ongoing exploration and appraisal efforts or, in the case of discoveries requiring government sanctioning, whether development negotiations are underway and proceeding as planned. If management determines that future appraisal drilling or development activities are unlikely to occur, associated suspended exploratory well costs are expensed. Acquisition costs of unproved properties are assessed for impairment at least annually and are transferred to proved oil and gas properties to the extent the costs are associated with successful exploration activities. Significant undeveloped leases are assessed individually for impairment based on the Company’s current exploration plans. Unproved oil and gas properties with individually insignificant lease acquisition costs are amortized on a group basis over the average lease term at rates that provide for full amortization of unsuccessful leases upon lease expiration or abandonment. Costs of expired or abandoned leases are charged to exploration expense, while costs of productive leases are transferred to proved oil and gas properties. Costs of maintaining and retaining unproved properties, as well as amortization of individually insignificant leases and impairment of unsuccessful leases, are included in exploration costs in the statement of consolidated operations. Costs to develop proved reserves, including the costs of all development wells and related equipment used in the production of crude oil and natural gas, are capitalized. Depreciation of the cost of proved oil and gas properties is calculated using the unit-of-production (UOP) method. The UOP calculation multiplies the percentage of estimated proved reserves produced each quarter by the carrying value of associated proved oil and gas properties. The reserve base used to calculate depreciation for leasehold acquisition costs and the cost to acquire proved properties is the sum of proved developed reserves and proved undeveloped reserves. The reserve base used to calculate the depreciation for capitalized well costs is the sum of proved developed reserves only. Estimated future dismantlement, restoration and abandonment costs, net of salvage values, are included in the depreciable cost. Oil and gas properties are grouped for depreciation in accordance with ASC 932, “Extractive Activities—Oil and Gas.” The basis for grouping is a reasonable aggregation of properties with a common geological structural feature or stratigraphic condition, such as a reservoir or field. When circumstances indicate that the carrying value of proved oil and gas properties may not be recoverable, the Company compares unamortized capitalized costs to the expected undiscounted pre-tax future cash flows for the associated assets grouped at the lowest level for which identifiable cash flows are independent of cash flows of other assets. If the expected undiscounted pre-tax future cash flows, based on Apache’s estimate of future crude oil and natural gas prices, operating costs, anticipated production from proved reserves and other relevant data, are lower than the unamortized capitalized cost, the capitalized cost is reduced to fair value. Fair value is generally estimated using the income approach described in ASC 820. The expected future cash flows used for impairment reviews and related fair value calculations are typically based on judgmental assessments, a Level 3 fair value measurement. The significant decline in oil and natural gas prices, as well as longer-term commodity price outlooks, related to reduced demand for oil and natural gas as a result of the COVID-19 pandemic and related governmental actions indicated possible impairment of the Company’s proved and unproved oil and gas properties. In addition to estimating risk-adjusted reserves and future production volumes, estimated future commodity prices are the largest driver in variability of undiscounted pre-tax cash flows. Expected cash flows were estimated based on management’s views of published West Texas Intermediate (WTI), Brent, and Henry Hub forward pricing as of the balance sheet dates. Other significant assumptions and inputs used to calculate estimated future cash flows include estimates for future development activity, exploration plans and remaining lease terms. A 10 percent discount rate, based on a market-based weighted-average cost of capital estimate, was applied to the undiscounted cash flow estimate to value all of Apache’s asset groups that were subject to impairment charges in the first and second quarters of 2020. The following table represents non-cash impairments of the carrying value of the Company’s proved and unproved properties: For the Quarter Ended September 30, For the Nine Months Ended September 30, 2020 2019 2020 2019 (In millions) Proved Properties: U.S. $ — $ — $ 3,938 $ 86 Egypt — — 374 — North Sea — — 7 — Total Proved $ — $ — $ 4,319 $ 86 Unproved Properties: U.S. $ 34 $ 10 $ 80 $ 217 Egypt 2 2 6 6 Total Unproved $ 36 $ 12 $ 86 $ 223 Proved properties impaired during the second and first quarters of 2020 had aggregate fair values of $32 million and $1.9 billion , respectively. On the statement of consolidated operations, unproved leasehold impairments are typically recorded as a component of “Exploration” expense; however, in the second quarter of 2019, unproved impairments of $149 million
Gathering, Processing, and Transmission Facilities	The Company assesses the carrying amount of its GPT facilities whenever events or changes in circumstances indicate that their carrying amount may not be recoverable. If the carrying amount of these facilities is more than the sum of the undiscounted cash flows, an impairment loss is recognized for the excess of the carrying value over its fair value. As discussed under “Fair Value Measurements” above, Apache assessed its long-lived infrastructure assets for impairment at March 31, 2020, and recorded an impairment of $68 million on its GPT assets in Egypt during the first quarter of 2020. The fair values of the impaired assets were determined to be $46 million and were estimated using the income approach. The income approach considered internal estimates based on future throughput volumes from applicable development concessions in Egypt and estimated costs to operate. These assumptions were applied based on throughput assumptions developed in relation to the oil and gas proved property impairment assessment as discussed above to develop future cash flow projections that were then discounted to estimated fair value, using a 10 percent discount rate, based on a market-based weighted-average cost of capital estimate. Apache has classified these non-recurring fair value measurements as Level 3 in the fair value hierarchy.
Revenue Recognition	There have been no significant changes to the Company’s contracts with customers during the nine months ended September 30, 2020 and 2019 . The third quarter and first nine months of 2019 include the reclassification of $30 million and $72 million , respectively, from “Other, net” to “Purchased oil and gas sales,” both within “Revenues and Other” and the respective associated $23 million and $60 million purchased oil and gas costs from “Other, net” within “Revenues and Other” to “Purchased oil and gas costs” within “Operating Expenses” on the Company’s consolidated statement of operations to conform to the current-year presentation. Upstream The Company’s upstream oil and gas segments primarily generate revenue from contracts with customers from the sale of its crude oil, natural gas, and natural gas liquids (NGLs) production volumes. Because the Company’s production fluctuates with potential operational issues and changes to development plans, Apache purchases third-party oil and gas to fulfill sales obligations and commitments. Sales proceeds related to third-party oil and gas purchases are also classified as revenue from customers. Under these short-term commodity sales contracts, the physical delivery of each unit of quantity represents a single, distinct performance obligation on behalf of the Company. Contract prices are determined based on market-indexed prices, adjusted for quality, transportation, and other market-reflective differentials. Revenue is measured by allocating an entirely variable market price to each performance obligation and recognized at a point in time when control is transferred to the customer. The Company considers a variety of facts and circumstances in assessing the point of control transfer, including but not limited to: whether the purchaser can direct the use of the hydrocarbons, the transfer of significant risks and rewards, and the Company’s right to payment. Control typically transfers to customers upon the physical delivery at specified locations within each contract and the transfer of title. Oil and gas production revenues from non-customers represent income taxes paid to the Arab Republic of Egypt by Egyptian General Petroleum Corporation on behalf of the Company. Revenue and associated expenses related to such tax volumes are recorded as “Oil, natural gas, and natural gas liquids production revenues” and “Current income tax provision,” respectively, in the Company’s statement of consolidated operations. Refer to Note 14—Business Segment Information for a disaggregation of revenue by product and reporting segment. Altus Midstream The Company’s Altus Midstream segment is operated by ALTM, through its subsidiary, Altus Midstream LP (collectively, Altus), and generates revenue from contracts with its customers from its gathering, compression, processing, and transmission services. These services are primarily provided on Apache’s natural gas and natural gas liquid production volumes. Under these long-term commercial service contracts, providing the related service represents a single, distinct performance obligation on behalf of Altus that is satisfied over time. In accordance with the terms of these agreements, Altus receives a fixed fee for each contract year, subject to yearly fee escalation recalculations. Revenue is measured using the output method and recognized in the amount to which Altus has the right to invoice, as performance completed to date corresponds directly with the value to its customers. For the periods presented, midstream segment revenues were primarily attributable to sales between Altus and Apache. All midstream revenues between Apache and Altus are fully eliminated upon consolidation. Payment Terms and Contract Balances Payments under all contracts with customers are typically due and received within a short-term period of one year or less, after physical delivery of the product or service has been rendered. Receivables from contracts with customers, net of allowance for credit losses, totaled $770 million and $945 million as of September 30, 2020 and December 31, 2019 , respectively. In accordance with the provisions of ASC 606, “Revenue from Contracts with Customers,” variable market prices for each short-term commodity sale are allocated entirely to each performance obligation as the terms of payment relate specifically to the Company’s efforts to satisfy its obligations. As such, the Company has elected the practical expedients available under the standard to not disclose the aggregate transaction price allocated to unsatisfied, or partially unsatisfied, performance obligations as of the end of the reporting period.
Accounts Receivable and Allowance for Credit Losses	Accounts receivable are stated at amortized cost net of an allowance for credit losses. The Company routinely assesses the collectability of its financial assets measured at amortized cost. In June 2016, the Financial Accounting Standards Board (FASB) issued ASU 2016-13, “Financial Instruments-Credit Losses.” The standard changes the impairment model for trade receivables, held-to-maturity debt securities, net investments in leases, loans, and other financial assets measured at amortized cost. This ASU requires the use of a new forward-looking “expected loss” model compared to the previous “incurred loss” model, resulting in accelerated recognition of credit losses. Apache adopted this update in the first quarter of 2020. This ASU primarily applies to the Company’s accounts receivable balances, of which the majority are due within 30 days. The Company monitors the credit quality of its counterparties through review of collections, credit ratings, and other analyses. The Company develops its estimated allowance for credit losses primarily using an aging method and analyses of historical loss rates as well as consideration of current and future conditions that could impact its counterparties’ credit quality and liquidity. The adoption and implementation of this ASU did not have a material impact on the Company’s financial statements.
New Pronouncements Issued but Not Yet Adopted	New Pronouncements Issued but Not Yet Adopted In August 2020, the FASB issued ASU 2020-06, “Debt-Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging-Contracts in Entity’s Own Equity (Subtopic 815-40)” to improve financial reporting associated with accounting for convertible instruments and contracts in an entity’s own equity. This update is effective for Apache beginning in the first quarter of 2022, with early adoption permitted, using either the modified or fully retrospective method with a cumulative effect adjustment to the opening balance of retained earnings. The Company is evaluating the effect of adoption of the ASU and does not believe it will have a material impact on its financial statements.

SUMMARY OF SIGNIFICANT ACCOUN_3

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)	9 Months Ended
	Sep. 30, 2020
Accounting Policies [Abstract]
Schedule of Asset Impairments	The following table presents a summary of asset impairments recorded in connection with fair value assessments: For the Quarter Ended September 30, For the Nine Months Ended September 30, 2020 2019 2020 2019 (In millions) Oil and gas proved property $ — $ — $ 4,319 $ 86 Gathering, processing, and transmission facilities — 9 68 9 Goodwill — — 87 — Divested unproved properties and leasehold — — — 149 Inventory and other — — 18 5 Total Impairments $ — $ 9 $ 4,492 $ 249
Schedule of Non-cash Impairments of Proved and Unproved Property and Equipment	The following table represents non-cash impairments of the carrying value of the Company’s proved and unproved properties: For the Quarter Ended September 30, For the Nine Months Ended September 30, 2020 2019 2020 2019 (In millions) Proved Properties: U.S. $ — $ — $ 3,938 $ 86 Egypt — — 374 — North Sea — — 7 — Total Proved $ — $ — $ 4,319 $ 86 Unproved Properties: U.S. $ 34 $ 10 $ 80 $ 217 Egypt 2 2 6 6 Total Unproved $ 36 $ 12 $ 86 $ 223

DERIVATIVE INSTRUMENTS AND HE_2

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES (Tables)	9 Months Ended
	Sep. 30, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Commodity Derivative Positions	As of September 30, 2020 , Apache had the following open crude oil derivative positions: Collars Production Period Settlement Index Mbbls Weighted Average Floor Sold Price Weighted Average Floor Purchased Price Weighted Average Ceiling Price October—December 2020 NYMEX WTI 1,748 $15.00 $20.00 $45.55 October—December 2020 Dated Brent 1,518 $15.00 $20.00 $51.63 As of September 30, 2020 , Apache had the following open crude oil financial basis swap contracts: Basis Swap Purchased Basis Swap Sold Production Period Settlement Index Mbbls Weighted Average Price Differential Mbbls Weighted Average Price Differential October—December 2020 Midland-WTI/Cushing-WTI — — 6,716 $(2.15) October—December 2020 Midland-WTI/Cushing-WTI 828 $0.20 — — As of September 30, 2020 , Apache had the following open natural gas financial basis swap contracts: Basis Swap Purchased Basis Swap Sold Production Period Settlement Index MMBtu (in 000’s) Weighted Average Price Differential MMBtu (in 000’s) Weighted Average Price Differential April—December 2021 Nymex Henry Hub/IF Waha 37,580 $(0.43) — — April—December 2021 Nymex Henry Hub/IF HSC — — 37,580 $(0.07) January—December 2022 Nymex Henry Hub/IF Waha 43,800 $(0.45) — — January—December 2022 Nymex Henry Hub/IF HSC — — 43,800 $(0.08)
Schedule of Derivative Assets Measured at Fair Value	The following table presents the Company’s derivative assets and liabilities measured at fair value on a recurring basis: Fair Value Measurements Using Quoted Price in Active Markets (Level 1) Significant Other Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total Fair Value Netting (1) Carrying Amount (In millions) September 30, 2020 Assets: Commodity Derivative Instruments $ — $ 12 $ — $ 12 $ (2 ) $ 10 Liabilities: Commodity Derivative Instruments $ — $ 15 $ — $ 15 $ (2 ) $ 13 Pipeline Capacity Embedded Derivatives — 54 — 54 — 54 Foreign Currency Derivative Instruments — 1 — 1 — 1 Preferred Units Embedded Derivative — — 179 179 — 179 December 31, 2019 Assets: Pipeline Capacity Embedded Derivative $ — $ 8 $ — $ 8 $ — $ 8 Foreign Currency Derivative Instruments — 1 — 1 — 1 Liabilities: Preferred Units Embedded Derivative — — 103 103 — 103 (1) The derivative fair values are based on analysis of each contract on a gross basis, excluding the impact of netting agreements with counterparties.
Schedule of Derivative Liabilities Measured at Fair Value	The following table presents the Company’s derivative assets and liabilities measured at fair value on a recurring basis: Fair Value Measurements Using Quoted Price in Active Markets (Level 1) Significant Other Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total Fair Value Netting (1) Carrying Amount (In millions) September 30, 2020 Assets: Commodity Derivative Instruments $ — $ 12 $ — $ 12 $ (2 ) $ 10 Liabilities: Commodity Derivative Instruments $ — $ 15 $ — $ 15 $ (2 ) $ 13 Pipeline Capacity Embedded Derivatives — 54 — 54 — 54 Foreign Currency Derivative Instruments — 1 — 1 — 1 Preferred Units Embedded Derivative — — 179 179 — 179 December 31, 2019 Assets: Pipeline Capacity Embedded Derivative $ — $ 8 $ — $ 8 $ — $ 8 Foreign Currency Derivative Instruments — 1 — 1 — 1 Liabilities: Preferred Units Embedded Derivative — — 103 103 — 103 (1) The derivative fair values are based on analysis of each contract on a gross basis, excluding the impact of netting agreements with counterparties.
Schedule of Fair Value Measurement Inputs	As of the September 30, 2020 valuation date, the Company used the forward B-rated Energy Bond Yield curve to develop the following key unobservable inputs used to value this embedded derivative: Quantitative Information About Level 3 Fair Value Measurements Fair Value at September 30, 2020 Valuation Technique Significant Unobservable Inputs Range/Value (In millions) Preferred Units Embedded Derivative $ 179 Option Model Altus’ Imputed Interest Rate 14.54-16.18% Interest Rate Volatility 35.32%
Schedule of Derivative Instruments on Consolidated Balance Sheet and Statement of Consolidated Operations	The carrying value of the Company’s derivative assets and liabilities and their locations on the consolidated balance sheet are as follows: September 30, 2020 December 31, 2019 (In millions) Current Assets: Other current assets $ 1 $ 2 Other Assets: Deferred charges and other 9 7 Total Assets $ 10 $ 9 Current Liabilities: Other current liabilities $ 14 $ — Deferred Credits and Other Noncurrent Liabilities: Other 233 103 Total Liabilities $ 247 $ 103 Derivative Activity Recorded in the Statement of Consolidated Operations The following table summarizes the effect of derivative instruments on the Company’s statement of consolidated operations: For the Quarter Ended September 30, For the Nine Months Ended September 30, 2020 2019 2020 2019 (In millions) Realized: Commodity derivative instruments $ (83 ) $ (16 ) $ (119 ) $ 30 Foreign currency derivative instruments — — (1 ) — Treasury-lock — — — (18 ) Realized gain (loss), net (83 ) (16 ) (120 ) 12 Unrealized: Commodity derivative instruments 91 (3 ) (3 ) (69 ) Pipeline capacity embedded derivatives 8 — (62 ) — Foreign currency derivative instruments 3 21 (1 ) 21 Preferred units embedded derivative (3 ) (4 ) (76 ) (4 ) Unrealized gain (loss), net 99 14 (142 ) (52 ) Derivative instrument gains (losses), net $ 16 $ (2 ) $ (262 ) $ (40 )

OTHER CURRENT ASSETS (Tables)

OTHER CURRENT ASSETS (Tables)	9 Months Ended
	Sep. 30, 2020
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Schedule of Other Current Assets	The following table provides detail of the Company’s other current assets as of September 30, 2020 and December 31, 2019 : September 30, 2020 December 31, 2019 (In millions) Inventories $ 503 $ 502 Drilling advances 102 92 Prepaid assets and other 53 58 Total Other current assets $ 658 $ 652

EQUITY METHOD INTERESTS (Tables

EQUITY METHOD INTERESTS (Tables)	9 Months Ended
	Sep. 30, 2020
Equity Method Investments and Joint Ventures [Abstract]
Summary of Equity Method Investment Information	The following presents summarized information of combined statement of operations for Altus’ equity method interests (on a 100 percent basis): For the Nine Months Ended September 30, 2020 2019 (1) (In millions) Operating revenues $ 531 $ 103 Operating expenses 264 62 Operating income 267 41 Net income 217 34 Other comprehensive loss (1 ) (11 ) (1) Although Altus’ interests in EPIC Crude Holdings, LP, Permian Highway Pipeline LLC, and Breviloba, LLC were acquired in March, May, and July 2019, respectively, the combined financial results are presented for the nine months ended September 30, 2019 for comparability. Interest September 30, 2020 December 31, 2019 (In millions) Gulf Coast Express Pipeline LLC 16.0 % $ 284 $ 291 EPIC Crude Holdings, LP 15.0 % 182 163 Permian Highway Pipeline LLC 26.7 % 576 311 Breviloba, LLC (Shin Oak Pipeline) 33.0 % 482 493 $ 1,524 $ 1,258 The following table presents the activity in Altus’ equity method interests for the nine months ended September 30, 2020 : Gulf Coast Express Pipeline LLC EPIC Crude Holdings, LP Permian Highway Pipeline LLC Breviloba, LLC Total (In millions) Balance at December 31, 2019 $ 291 $ 163 $ 311 $ 493 $ 1,258 Capital contributions 1 27 258 — 286 Distributions (39 ) — — (35 ) (74 ) Capitalized interest — — 7 — 7 Equity income (loss), net 31 (8 ) — 24 47 Balance at September 30, 2020 $ 284 $ 182 $ 576 $ 482 $ 1,524

OTHER CURRENT LIABILITIES (Tabl

OTHER CURRENT LIABILITIES (Tables)	9 Months Ended
	Sep. 30, 2020
Payables and Accruals [Abstract]
Schedule of Other Current Liabilities	The following table provides detail of the Company’s other current liabilities as of September 30, 2020 and December 31, 2019 : September 30, 2020 December 31, 2019 (In millions) Accrued operating expenses $ 99 $ 143 Accrued exploration and development 158 319 Accrued gathering, processing, and transmission - Altus 1 17 Accrued compensation and benefits 116 212 Accrued interest 111 135 Accrued income taxes 18 51 Current asset retirement obligation 47 47 Current operating lease liability 110 169 Current derivative liability 14 — Other 129 56 Total Other current liabilities $ 803 $ 1,149

ASSET RETIREMENT OBLIGATION (Ta

ASSET RETIREMENT OBLIGATION (Tables)	9 Months Ended
	Sep. 30, 2020
Asset Retirement Obligation Disclosure [Abstract]
Schedule of Asset Retirement Obligation	The following table describes changes to the Company’s asset retirement obligation (ARO) liability for the nine -month period ended September 30, 2020 : (In millions) Asset retirement obligation at December 31, 2019 $ 1,858 Liabilities incurred 10 Liabilities settled (23 ) Liabilities divested (20 ) Accretion expense 81 Asset retirement obligation at September 30, 2020 1,906 Less current portion (47 ) Asset retirement obligation, long-term $ 1,859

DEBT AND FINANCING COSTS (Table

DEBT AND FINANCING COSTS (Tables)	9 Months Ended
	Sep. 30, 2020
Debt Disclosure [Abstract]
Schedule of Debt	The following table presents the carrying value of the Company’s debt: September 30, 2020 December 31, 2019 (In millions) Notes and debentures before unamortized discount and debt issuance costs (1) $ 8,324 $ 8,217 Altus credit facility (2) 580 396 Apache credit facility (2) 87 — Finance lease obligations 37 48 Unamortized discount (35 ) (42 ) Debt issuance costs (59 ) (53 ) Total debt 8,934 8,566 Current maturities (184 ) (11 ) Long-term debt $ 8,750 $ 8,555 (1) The fair values of the Company’s notes and debentures were $7.6 billion and $8.4 billion as of September 30, 2020 and December 31, 2019 , respectively. Apache uses a market approach to determine the fair values of its notes and debentures using estimates provided by an independent investment financial data services firm (a Level 2 fair value measurement). (2) The carrying amount of borrowings on credit facilities approximates fair value because the interest rates are variable and reflective of market rates.
Schedule of Financing Costs, Net	The following table presents the components of Apache’s financing costs, net: For the Quarter Ended September 30, For the Nine Months Ended September 30, 2020 2019 2020 2019 (In millions) Interest expense $ 113 $ 107 $ 327 $ 323 Amortization of debt issuance costs 2 2 6 5 Capitalized interest (3 ) (9 ) (9 ) (26 ) Loss (gain) on extinguishment of debt (12 ) — (152 ) 75 Interest income (1 ) (5 ) (4 ) (12 ) Financing costs, net $ 99 $ 95 $ 168 $ 365

REDEMABLE NONCONTROLLING INTE_2

REDEMABLE NONCONTROLLING INTEREST - ALTUS (Tables)	9 Months Ended
	Sep. 30, 2020
Equity [Abstract]
Schedule of Preferred Units	Activity related to the Preferred Units during the nine months ended September 30, 2020 is as follows: Units Outstanding Financial Position (1) (In millions, except unit data) Redeemable noncontrolling interest - Altus Preferred Unit limited partners: at December 31, 2019 638,163 $ 555 Distribution of in-kind additional Preferred Units 22,531 — Cash distributions to Altus Preferred Unit limited partners — (11 ) Allocation of Altus Midstream LP net income N/A 56 Redeemable noncontrolling interest - Altus Preferred Unit limited partners: at September 30, 2020 660,694 600 Preferred Units embedded derivative 179 $ 779 (1) The Preferred Units are redeemable at Altus Midstream LP’s option at September 30, 2020 at a price (the Redemption Price) equal to (a) the greater of (i) an 11.5 percent internal rate of return and (ii) a 1.3 times multiple of invested capital. As of September 30, 2020 , the greater of these two amounts was a 1.3 times multiple of invested capital which equaled $813 million . As of September 30, 2020 , the aggregate Redemption Price using an 11.5 percent internal rate of return was $709 million . N/A - not applicable. The net transaction price was allocated to the preferred redeemable noncontrolling interest and the embedded features according to the associated initial fair value measurements as follows: June 12, 2019 (In millions) Redeemable noncontrolling interest - Altus Preferred Unit limited partners $ 517 Preferred Units embedded derivative 94 $ 611

CAPITAL STOCK (Tables)

CAPITAL STOCK (Tables)	9 Months Ended
	Sep. 30, 2020
Equity [Abstract]
Schedule Reconciliation of the Components of Basic and Diluted Net Loss Per Common Share	A reconciliation of the components of basic and diluted net loss per common share for the periods presented in the consolidated financial statements is shown in the tables below. For the Quarter Ended September 30, 2020 2019 Loss Shares Per Share Loss Shares Per Share (In millions, except per share amounts) Basic: Loss attributable to common stock $ (4 ) 378 $ (0.01 ) $ (170 ) 377 $ (0.45 ) Effect of Dilutive Securities: Stock options and other $ — — $ — $ — — $ — Redeemable noncontrolling interest - Altus Preferred Unit limited partners $ (4 ) — $ (0.01 ) $ — — $ — Diluted: Loss attributable to common stock $ (8 ) 378 $ (0.02 ) $ (170 ) 377 $ (0.45 ) For the Nine Months Ended September 30, 2020 2019 Loss Shares Per Share Loss Shares Per Share (In millions, except per share amounts) Basic: Loss attributable to common stock $ (4,870 ) 378 $ (12.89 ) $ (577 ) 377 $ (1.53 ) Effect of Dilutive Securities: Stock options and other $ — — $ — $ — — $ — Diluted: Loss attributable to common stock $ (4,870 ) 378 $ (12.89 ) $ (577 ) 377 $ (1.53 )

BUSINESS SEGMENT INFORMATION (T

BUSINESS SEGMENT INFORMATION (Tables)	9 Months Ended
	Sep. 30, 2020
Segment Reporting [Abstract]
Schedule of Financial Segment Information	Financial information for each segment is presented below: Egypt (1) North Sea U.S. Altus Intersegment Eliminations & Other Total (2) Upstream Midstream (In millions) For the Quarter Ended September 30, 2020 Revenues: Oil revenues $ 303 $ 179 $ 303 $ — $ — $ 785 Natural gas revenues 74 13 77 — — 164 Natural gas liquids revenues 2 5 90 — — 97 Oil, natural gas, and natural gas liquids production revenues 379 197 470 — — 1,046 Purchased oil and gas sales — — 73 1 — 74 Midstream service affiliate revenues — — — 39 (39 ) — 379 197 543 40 (39 ) 1,120 Operating Expenses: Lease operating expenses 102 79 79 — (1 ) 259 Gathering, processing, and transmission 8 10 74 9 (38 ) 63 Purchased oil and gas costs — — 74 1 — 75 Taxes other than income — — 30 4 — 34 Exploration 10 10 34 — 4 58 Depreciation, depletion, and amortization 144 90 161 3 — 398 Asset retirement obligation accretion — 18 8 1 — 27 264 207 460 18 (35 ) 914 Operating Income (Loss) (3) $ 115 $ (10 ) $ 83 $ 22 $ (4 ) 206 Other Income (Expense): Derivative instrument gains, net 16 Loss on divestitures, net (1 ) Other, net 9 General and administrative (52 ) Transaction, reorganization, and separation (7 ) Financing costs, net (99 ) Income Before Income Taxes $ 72 Egypt (1) North Sea U.S. Altus Intersegment Eliminations & Other Total (2) Upstream Midstream (In millions) For the Nine Months Ended September 30, 2020 Revenues: Oil revenues $ 823 $ 578 $ 929 $ — $ — $ 2,330 Natural gas revenues 209 39 169 — — 417 Natural gas liquids revenues 6 15 211 — — 232 Oil, natural gas, and natural gas liquids production revenues 1,038 632 1,309 — — 2,979 Purchased oil and gas sales — — 235 2 — 237 Midstream service affiliate revenues — — — 111 (111 ) — 1,038 632 1,544 113 (111 ) 3,216 Operating Expenses: Lease operating expenses 312 234 313 — (1 ) 858 Gathering, processing, and transmission 31 37 219 29 (110 ) 206 Purchased oil and gas costs — — 205 2 — 207 Taxes other than income — — 79 11 — 90 Exploration 51 26 100 — 10 187 Depreciation, depletion, and amortization 463 278 632 9 — 1,382 Asset retirement obligation accretion — 54 24 3 — 81 Impairments 529 7 3,956 — — 4,492 1,386 636 5,528 54 (101 ) 7,503 Operating Income (Loss) (3) $ (348 ) $ (4 ) $ (3,984 ) $ 59 $ (10 ) (4,287 ) Other Income (Expense): Derivative instrument losses, net (262 ) Gain on divestitures 24 Other 41 General and administrative (214 ) Transaction, reorganization, and separation (44 ) Financing costs, net (168 ) Loss Before Income Taxes $ (4,910 ) Total Assets (4) $ 3,052 $ 2,238 $ 5,708 $ 1,741 $ 136 $ 12,875 Egypt (1) North Sea U.S. Altus Intersegment Eliminations & Other Total (2) Upstream Midstream (In millions) For the Quarter Ended September 30, 2019 Revenues: Oil revenues $ 472 $ 231 $ 504 $ — $ — $ 1,207 Natural gas revenues 72 14 50 — — 136 Natural gas liquids revenues 2 5 88 — — 95 Oil, natural gas, and natural gas liquids production revenues 546 250 642 — — 1,438 Purchased oil and gas sales — — 30 — — 30 Midstream service affiliate revenues — — — 34 (34 ) — 546 250 672 34 (34 ) 1,468 Operating Expenses: Lease operating expenses 115 76 159 — — 350 Gathering, processing, and transmission 9 9 69 13 (34 ) 66 Purchased oil and gas costs — — 23 — — 23 Taxes other than income — — 41 3 — 44 Exploration 27 — 25 — 4 56 Depreciation, depletion, and amortization 177 71 452 11 — 711 Asset retirement obligation accretion — 19 8 — — 27 Impairments — — — 9 — 9 328 175 777 36 (30 ) 1,286 Operating Income (Loss) (3) $ 218 $ 75 $ (105 ) $ (2 ) $ (4 ) 182 Other Income (Expense): Derivative instrument losses, net (2 ) Other 34 General and administrative (98 ) Transaction, reorganization, and separation (7 ) Financing costs, net (95 ) Income Before Income Taxes $ 14 Egypt (1) North Sea U.S. Altus Intersegment Eliminations & Other Total (2) Upstream Midstream (In millions) For the Nine Months Ended September 30, 2019 Revenues: Oil revenues $ 1,509 $ 868 $ 1,537 $ — $ — $ 3,914 Natural gas revenues 223 64 203 — — 490 Natural gas liquids revenues 9 16 261 — — 286 Oil, natural gas, and natural gas liquids production revenues 1,741 948 2,001 — — 4,690 Purchased oil and gas sales — — 72 — — 72 Midstream service affiliate revenues — — — 92 (92 ) — 1,741 948 2,073 92 (92 ) 4,762 Operating Expenses: Lease operating expenses 365 240 501 — (2 ) 1,104 Gathering, processing, and transmission 31 32 214 43 (90 ) 230 Purchased oil and gas costs — — 60 — — 60 Taxes other than income — — 131 10 — 141 Exploration 89 2 117 — 12 220 Depreciation, depletion, and amortization 538 269 1,125 27 — 1,959 Asset retirement obligation accretion — 56 23 1 — 80 Impairments — — 240 9 — 249 1,023 599 2,411 90 (80 ) 4,043 Operating Income (Loss) (3) $ 718 $ 349 $ (338 ) $ 2 $ (12 ) 719 Other Income (Expense): Derivative instrument losses, net (40 ) Gain on divestitures, net 20 Other, net 33 General and administrative (323 ) Transaction, reorganization, and separation (17 ) Financing costs, net (365 ) Income Before Income Taxes $ 27 Total Assets (4) $ 3,851 $ 2,529 $ 12,289 $ 2,648 $ 88 $ 21,405 (1) Includes revenue from non-customers of: For the Quarter Ended September 30, For the Nine Months Ended September 30, 2020 2019 2020 2019 (In millions) Oil $ 38 $ 98 $ 65 $ 316 Natural gas 6 9 9 30 Natural gas liquids — — — 1 (2) Includes a noncontrolling interest in Egypt and Altus. (3) The operating income of U.S. and Egypt includes leasehold and other asset impairments totaling $34 million and $2 million , respectively, for the third quarter of 2020 . The operating loss of U.S., Egypt, and North Sea includes leasehold and other asset impairments totaling $4.0 billion , $535 million , and $7 million , respectively, for the first nine months of 2020. The operating income (loss) of U.S., Altus Midstream, and Egypt includes leasehold and other asset impairments totaling $10 million , $9 million and $2 million , respectively, for the third quarter of 2019 . The operating income (loss) of U.S., Altus Midstream, and Egypt includes leasehold and other asset impairments totaling $308 million , $9 million , and $6 million , respectively, for the first nine months of 2019 . (4) Intercompany balances are excluded from total assets.

SUMMARY OF SIGNIFICANT ACCOUN_4

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Additional Information (Details) - USD ($)	3 Months Ended					9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Jun. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Schedule Of Significant Accounting Policies [Line Items]
Impairments	$ 0	$ 20,000,000	$ 4,500,000,000	$ 9,000,000		$ 4,492,000,000	$ 249,000,000
Impairments of oil and gas properties	0			9,000,000		4,492,000,000	249,000,000
Goodwill	0		87,000,000	0		87,000,000	0
Impairment for early termination of drilling rig leases			13,000,000
Inventory write-down			5,000,000
Divested unproved properties and leasehold	0			0		0	149,000,000
Receivables from contracts with customer, net	770,000,000					770,000,000		$ 945,000,000
Transaction, reorganization, and separation	7,000,000			7,000,000		44,000,000	17,000,000
Separation costs
Schedule Of Significant Accounting Policies [Line Items]
Transaction, reorganization, and separation						41,000,000
Consulting fees
Schedule Of Significant Accounting Policies [Line Items]
Transaction, reorganization, and separation						2,000,000
Office closure
Schedule Of Significant Accounting Policies [Line Items]
Transaction, reorganization, and separation						1,000,000
Reorganization
Schedule Of Significant Accounting Policies [Line Items]
Restructuring cumulative cost incurred to date	69,000,000					69,000,000
Oil and gas, purchased
Schedule Of Significant Accounting Policies [Line Items]
Oil and gas production revenues	74,000,000			30,000,000		237,000,000	72,000,000
Cost of goods and services sold	75,000,000			23,000,000		207,000,000	60,000,000
Altus Midstream
Schedule Of Significant Accounting Policies [Line Items]
Assets held-for-sale, fair value				18,000,000			18,000,000
Oklahoma And Texas
Schedule Of Significant Accounting Policies [Line Items]
Impairments of oil and gas properties					$ 240,000,000
Oil and gas proved property
Schedule Of Significant Accounting Policies [Line Items]
Impairments of oil and gas properties	$ 0			0		$ 4,319,000,000	86,000,000
Oil and gas properties impaired, fair value		$ 1,900,000,000	32,000,000
Oil and gas proved property | Discount Rate | Significant Unobservable Inputs (Level 3)
Schedule Of Significant Accounting Policies [Line Items]
Oil and gas properties, measurement inputs	0.10					0.10
Oil and gas proved property | U.S.
Schedule Of Significant Accounting Policies [Line Items]
Impairments of oil and gas properties	$ 0		3,900,000,000	0		$ 3,938,000,000	86,000,000
Oil and gas proved property | Egypt
Schedule Of Significant Accounting Policies [Line Items]
Impairments of oil and gas properties	0		354,000,000	0		374,000,000	0
Oil and gas proved property | North Sea
Schedule Of Significant Accounting Policies [Line Items]
Impairments of oil and gas properties	0		7,000,000	0		7,000,000	0
Oil and gas proved property | Oklahoma And Texas
Schedule Of Significant Accounting Policies [Line Items]
Impairments of oil and gas properties					86,000,000
Gathering, processing, and transmission facilities
Schedule Of Significant Accounting Policies [Line Items]
Impairments			$ 68,000,000
Oil and gas properties impaired, fair value	$ 46,000,000					$ 46,000,000
Gathering, processing, and transmission facilities | Discount Rate | Significant Unobservable Inputs (Level 3)
Schedule Of Significant Accounting Policies [Line Items]
Oil and gas properties, measurement inputs	0.10					0.10
Oil and gas unproved properties
Schedule Of Significant Accounting Policies [Line Items]
Impairments of oil and gas properties	$ 36,000,000			12,000,000		$ 86,000,000	223,000,000
Oil and gas unproved properties | U.S.
Schedule Of Significant Accounting Policies [Line Items]
Impairments of oil and gas properties	34,000,000			10,000,000		80,000,000	217,000,000
Oil and gas unproved properties | Egypt
Schedule Of Significant Accounting Policies [Line Items]
Impairments of oil and gas properties	$ 2,000,000			$ 2,000,000		$ 6,000,000	$ 6,000,000
Oil and gas unproved properties | Oklahoma And Texas
Schedule Of Significant Accounting Policies [Line Items]
Impairments of oil and gas properties					149,000,000
Divested unproved properties and leasehold					149,000,000
Other working capital | Oklahoma And Texas
Schedule Of Significant Accounting Policies [Line Items]
Impairments of oil and gas properties					$ 5,000,000
Altus Midstream Company
Schedule Of Significant Accounting Policies [Line Items]
Ownership percentage by noncontrolling owners	21.00%					21.00%
Sinopec | Apache’s Egypt Oil And Gas Business
Schedule Of Significant Accounting Policies [Line Items]
Ownership percentage by noncontrolling owners	33.33%					33.33%

SUMMARY OF SIGNIFICANT ACCOUN_5

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Asset Impairments Recorded in Connection with Fair Value Assessments (Details) - USD ($)	3 Months Ended				9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Schedule Of Significant Accounting Policies [Line Items]
Goodwill	$ 0		$ 87,000,000	$ 0	$ 87,000,000	$ 0
Divested unproved properties and leasehold	0			0	0	149,000,000
Inventory and other	0			0	18,000,000	5,000,000
Total Impairments	0	$ 20,000,000	4,500,000,000	9,000,000	4,492,000,000	249,000,000
Oil and gas proved property
Schedule Of Significant Accounting Policies [Line Items]
Tangible asset impairment charges	0			0	4,319,000,000	86,000,000
Gathering, processing, and transmission facilities
Schedule Of Significant Accounting Policies [Line Items]
Tangible asset impairment charges	$ 0			$ 9,000,000	$ 68,000,000	$ 9,000,000
Total Impairments			$ 68,000,000

SUMMARY OF SIGNIFICANT ACCOUN_6

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Non-Cash Impairments of Proved and Unproved Property and Equipment (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Schedule Of Significant Accounting Policies [Line Items]
Asset impairments for property and equipment	$ 0		$ 9	$ 4,492	$ 249
Oil and gas proved property
Schedule Of Significant Accounting Policies [Line Items]
Asset impairments for property and equipment	0		0	4,319	86
Oil and gas unproved properties
Schedule Of Significant Accounting Policies [Line Items]
Asset impairments for property and equipment	36		12	86	223
U.S. | Oil and gas proved property
Schedule Of Significant Accounting Policies [Line Items]
Asset impairments for property and equipment	0	$ 3,900	0	3,938	86
U.S. | Oil and gas unproved properties
Schedule Of Significant Accounting Policies [Line Items]
Asset impairments for property and equipment	34		10	80	217
Egypt | Oil and gas proved property
Schedule Of Significant Accounting Policies [Line Items]
Asset impairments for property and equipment	0	354	0	374	0
Egypt | Oil and gas unproved properties
Schedule Of Significant Accounting Policies [Line Items]
Asset impairments for property and equipment	2		2	6	6
North Sea | Oil and gas proved property
Schedule Of Significant Accounting Policies [Line Items]
Asset impairments for property and equipment	$ 0	$ 7	$ 0	$ 7	$ 0

ACQUISITIONS AND DIVESTITURES -

ACQUISITIONS AND DIVESTITURES - Additional Information (Details) - USD ($)	1 Months Ended	3 Months Ended				9 Months Ended
	Dec. 31, 2019	Sep. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Jun. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Business Acquisition [Line Items]
Leasehold and property acquisitions		$ 0				$ 3,000,000	$ 39,000,000
Proceeds from sale of oil and gas properties						132,000,000	590,000,000
Block 58 Offshore Suriname
Business Acquisition [Line Items]
Ownership percentage by noncontrolling owners	50.00%
Proceeds received from joint venture	$ 100,000,000
Proceeds from joint venture agreement, for reimbursement of cost incurred	$ 79,000,000
Joint venture agreement, percentage of costs incurred for reimbursement	50.00%
Proceeds expected to receive from joint venture	$ 5,000,000,000
Joint venture agreement, future consideration term, appraisal and development capital cap	$ 7,500,000,000
Joint venture agreement, percentage of consideration carried on appraisal and development capital	25.00%
Joint venture agreement, additional cash payment to receive upon achieving of first production	$ 75,000,000
Disposed of by Sale
Business Acquisition [Line Items]
Gain (loss) on sale of non-core assets						5,000,000
Permian Basin
Business Acquisition [Line Items]
Leasehold and property acquisitions				$ 5,000,000		3,000,000	39,000,000
Permian Basin | Disposed of by Sale
Business Acquisition [Line Items]
Proceeds from sale of oil and gas properties						$ 53,000,000	21,000,000
Gain (loss) on sale of non-core assets							$ 12,000,000
Oklahoma | Disposed of by Sale
Business Acquisition [Line Items]
Proceeds from sale of oil and gas properties					$ 223,000,000
Gain (loss) on sale of non-core assets			$ 19,000,000		$ 17,000,000

ACQUISITIONS AND DIVESTITURES_2

ACQUISITIONS AND DIVESTITURES - 2019 Activity (Details) - USD ($)	3 Months Ended				9 Months Ended
	Sep. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Jun. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Business Acquisition [Line Items]
Property and equipment, net	$ 9,067,000,000				$ 9,067,000,000		$ 14,158,000,000
Proceeds from sale of oil and gas properties					132,000,000	$ 590,000,000
Asset impairments for property and equipment	0		$ 9,000,000		4,492,000,000	249,000,000
Leasehold and property acquisitions	$ 0				3,000,000	39,000,000
Disposed of by Sale
Business Acquisition [Line Items]
Gain (loss) on sale of non-core assets					5,000,000
Oklahoma And Texas
Business Acquisition [Line Items]
Asset impairments for property and equipment				$ 240,000,000
Oklahoma And Texas | Disposed of by Sale
Business Acquisition [Line Items]
Proceeds from sale of oil and gas properties			322,000,000
Gain (loss) on sale of non-core assets			7,000,000
Asset retirement obligations assumed			49,000,000
Asset impairments for property and equipment			240,000,000
Oklahoma | Disposed of by Sale
Business Acquisition [Line Items]
Property and equipment, net				206,000,000
Proceeds from sale of oil and gas properties				223,000,000
Gain (loss) on sale of non-core assets		$ 19,000,000		$ 17,000,000
Permian Region
Business Acquisition [Line Items]
Leasehold and property acquisitions			$ 5,000,000		3,000,000	39,000,000
Permian Region | Disposed of by Sale
Business Acquisition [Line Items]
Proceeds from sale of oil and gas properties					$ 53,000,000	21,000,000
Gain (loss) on sale of non-core assets						$ 12,000,000

CAPITALIZED EXPLORATORY WELL _2

CAPITALIZED EXPLORATORY WELL COSTS (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Extractive Industries [Abstract]
Capitalized exploratory well costs	$ 195	$ 141
Capitalized exploratory well costs that have been capitalized for period greater than one year		$ 14

DERIVATIVE INSTRUMENTS AND HE_3

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES - Derivative Instruments (Details) MMBTU in Thousands, MBbls in Thousands, £ in Millions	9 Months Ended
	Sep. 30, 2020GBP (£)$ / MMBTU$ / bblMMBTUCounterpartyMBbls
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Number of derivative counterparties | Counterparty	12
Collars | October—December 2020 | Crude Oil | NYMEX WTI
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, nonmonetary notional amount (in Mbbls) | MBbls	1,748
Derivative, weighted average floor sold price (USD per bbl)	15
Derivative, weighted average floor purchased price (USD per bbl)	20
Derivative, weighted average ceiling price (USD per bbl)	45.55
Collars | October—December 2020 | Crude Oil | Dated Brent
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, nonmonetary notional amount (in Mbbls) | MBbls	1,518
Derivative, weighted average floor sold price (USD per bbl)	15
Derivative, weighted average floor purchased price (USD per bbl)	20
Derivative, weighted average ceiling price (USD per bbl)	51.63
Collars | Calendar year 2020
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, weighted average ceiling price (USD per bbl)	1.38
Derivative, notional amount | £	£ 13.5
Derivative, weighted average floor price (USD per bbl)	1.26
Basis Swap Purchased | October—December 2020 | Crude Oil | Midland-WTI/Cushing-WTI
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, nonmonetary notional amount (in Mbbls) | MBbls	828
Weighted average price differential	0.20
Basis Swap Purchased | April—December 2021 | Natural Gas | Nymex Henry Hub/IF Waha
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, nonmonetary notional amount (in MMBtu) | MMBTU	37,580
Weighted average price differential | $ / MMBTU	(0.43)
Basis Swap Purchased | January—December 2022 | Natural Gas | Nymex Henry Hub/IF Waha
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, nonmonetary notional amount (in MMBtu) | MMBTU	43,800
Weighted average price differential | $ / MMBTU	(0.45)
Basis Swap Sold | October—December 2020 | Crude Oil | Midland-WTI/Cushing-WTI
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, nonmonetary notional amount (in Mbbls) | MBbls	6,716
Weighted average price differential	(2.15)
Basis Swap Sold | April—December 2021 | Natural Gas | Nymex Henry Hub/IF HSC
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, nonmonetary notional amount (in MMBtu) | MMBTU	37,580
Weighted average price differential | $ / MMBTU	(0.07)
Basis Swap Sold | January—December 2022 | Natural Gas | Nymex Henry Hub/IF HSC
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, nonmonetary notional amount (in MMBtu) | MMBTU	43,800
Weighted average price differential | $ / MMBTU	(0.08)

DERIVATIVE INSTRUMENTS AND HE_4

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES - Schedule of Derivative Assets and Liabilities Measured at Fair Value (Details) - Recurring - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Assets:
Derivative asset	$ 10	$ 9
Liabilities:
Derivative liability	247	103
Commodity Derivative Instruments
Assets:
Derivative asset, fair value	12
Derivative asset, netting	(2)
Derivative asset	10
Liabilities:
Derivative liability, fair value	15
Derivative liability, netting	(2)
Derivative liability	13
Commodity Derivative Instruments | Quoted Price in Active Markets (Level 1)
Assets:
Derivative asset, fair value	0
Liabilities:
Derivative liability, fair value	0
Commodity Derivative Instruments | Significant Other Inputs (Level 2)
Assets:
Derivative asset, fair value	12
Liabilities:
Derivative liability, fair value	15
Commodity Derivative Instruments | Significant Unobservable Inputs (Level 3)
Assets:
Derivative asset, fair value	0
Liabilities:
Derivative liability, fair value	0
Pipeline Capacity Embedded Derivatives
Assets:
Derivative asset, fair value		8
Derivative asset, netting		0
Derivative asset		8
Liabilities:
Derivative liability, fair value	54
Derivative liability, netting	0
Derivative liability	54
Pipeline Capacity Embedded Derivatives | Quoted Price in Active Markets (Level 1)
Assets:
Derivative asset, fair value		0
Liabilities:
Derivative liability, fair value	0
Pipeline Capacity Embedded Derivatives | Significant Other Inputs (Level 2)
Assets:
Derivative asset, fair value		8
Liabilities:
Derivative liability, fair value	54
Pipeline Capacity Embedded Derivatives | Significant Unobservable Inputs (Level 3)
Assets:
Derivative asset, fair value		0
Liabilities:
Derivative liability, fair value	0
Foreign Currency Derivative Instruments
Assets:
Derivative asset, fair value		1
Derivative asset, netting		0
Derivative asset		1
Liabilities:
Derivative liability, fair value	1
Derivative liability, netting	0
Derivative liability	1
Foreign Currency Derivative Instruments | Quoted Price in Active Markets (Level 1)
Assets:
Derivative asset, fair value		0
Liabilities:
Derivative liability, fair value	0
Foreign Currency Derivative Instruments | Significant Other Inputs (Level 2)
Assets:
Derivative asset, fair value		1
Liabilities:
Derivative liability, fair value	1
Foreign Currency Derivative Instruments | Significant Unobservable Inputs (Level 3)
Assets:
Derivative asset, fair value		0
Liabilities:
Derivative liability, fair value	0
Preferred Units Embedded Derivative
Liabilities:
Derivative liability, fair value	179	103
Derivative liability, netting	0	0
Derivative liability	179	103
Preferred Units Embedded Derivative | Quoted Price in Active Markets (Level 1)
Liabilities:
Derivative liability, fair value	0	0
Preferred Units Embedded Derivative | Significant Other Inputs (Level 2)
Liabilities:
Derivative liability, fair value	0	0
Preferred Units Embedded Derivative | Significant Unobservable Inputs (Level 3)
Liabilities:
Derivative liability, fair value	$ 179	$ 103

DERIVATIVE INSTRUMENTS AND HE_5

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES - Fair Value Measurement Inputs (Details) - Altus Midstream LP $ in Millions	Sep. 30, 2020USD ($)	Dec. 31, 2019	Jun. 12, 2019USD ($)
Derivative [Line Items]
Embedded derivative	$ 179		$ 94
Significant Unobservable Inputs (Level 3) | Measurement Input, Risk Free Interest Rate | Minimum
Derivative [Line Items]
Embedded derivative liability, measurement input	0.1454	0.0960
Significant Unobservable Inputs (Level 3) | Measurement Input, Risk Free Interest Rate | Maximum
Derivative [Line Items]
Embedded derivative liability, measurement input	0.1618	0.1268
Significant Unobservable Inputs (Level 3) | Measurement Input, Interest Rate Volatility
Derivative [Line Items]
Embedded derivative liability, measurement input	0.3532	0.2189

DERIVATIVE INSTRUMENTS AND HE_6

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES - Schedule of Derivative Assets and Liabilities and Locations on Consolidated Balance Sheet (Details) - Recurring - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Derivatives, Fair Value [Line Items]
Derivative asset	$ 10	$ 9
Derivative liability	247	103
Current Assets: Other current assets
Derivatives, Fair Value [Line Items]
Derivative asset	1	2
Other Assets: Deferred charges and other
Derivatives, Fair Value [Line Items]
Derivative asset	9	7
Current Liabilities: Other current liabilities
Derivatives, Fair Value [Line Items]
Derivative liability	14	0
Deferred Credits and Other Noncurrent Liabilities: Other
Derivatives, Fair Value [Line Items]
Derivative liability	$ 233	$ 103

DERIVATIVE INSTRUMENTS AND HE_7

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES - Schedule of Derivative Activities Recorded in the Statement of Consolidated Operations (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized gain (loss), net			$ (142)	$ (52)
Not Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Realized gain (loss), net	$ (83)	$ (16)	(120)	12
Unrealized gain (loss), net	99	14	(142)	(52)
Derivative instrument gains (losses), net	16	(2)	(262)	(40)
Commodity derivative instruments | Not Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Realized gain (loss), net	(83)	(16)	(119)	30
Unrealized gain (loss), net	91	(3)	(3)	(69)
Pipeline capacity embedded derivatives | Not Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized gain (loss), net	8	0	(62)	0
Foreign currency derivative instruments | Not Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Realized gain (loss), net	0	0	(1)	0
Unrealized gain (loss), net	3	21	(1)	21
Preferred units embedded derivative | Not Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized gain (loss), net	(3)	(4)	(76)	(4)
Treasury-lock | Not Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Realized gain (loss), net	$ 0	$ 0	$ 0	$ (18)

OTHER CURRENT ASSETS (Details)

OTHER CURRENT ASSETS (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Inventories	$ 503	$ 502
Drilling advances	102	92
Prepaid assets and other	53	58
Total Other current assets	$ 658	$ 652

EQUITY METHOD INTERESTS - Summa

EQUITY METHOD INTERESTS - Summary of Investments (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Schedule of Equity Method Investments [Line Items]
Equity method interests	$ 1,524	$ 1,258
Altus Midstream Company
Schedule of Equity Method Investments [Line Items]
Equity method interests	$ 1,524	1,258
Altus Midstream Company | Gulf Coast Express Pipeline LLC
Schedule of Equity Method Investments [Line Items]
Interest percentage	16.00%
Equity method interests	$ 284	291
Altus Midstream Company | EPIC Crude Holdings, LP
Schedule of Equity Method Investments [Line Items]
Interest percentage	15.00%
Equity method interests	$ 182	163
Altus Midstream Company | Permian Highway Pipeline LLC
Schedule of Equity Method Investments [Line Items]
Interest percentage	26.70%
Equity method interests	$ 576	311
Altus Midstream Company | Breviloba, LLC (Shin Oak Pipeline)
Schedule of Equity Method Investments [Line Items]
Interest percentage	33.00%
Equity method interests	$ 482	$ 493

EQUITY METHOD INTERESTS - Narra

EQUITY METHOD INTERESTS - Narrative (Details) - Altus Midstream Company $ in Millions	Sep. 30, 2020USD ($)entity	Dec. 31, 2019USD ($)
Schedule of Equity Method Investments [Line Items]
Number of long-haul pipeline entities | entity	4
Difference between carrying amount and underlying equity amount | $	$ 37	$ 30

EQUITY METHOD INTERESTS - Rollf

EQUITY METHOD INTERESTS - Rollforward Activity (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Movement In Equity Method Interests [Roll Forward]
Equity method interest, beginning balance	$ 1,258
Capital contributions	286	$ 338
Equity method interest, ending balance	1,524
Breviloba, LLC
Movement In Equity Method Interests [Roll Forward]
Distributions	(35)
Altus Midstream Company
Movement In Equity Method Interests [Roll Forward]
Equity method interest, beginning balance	1,258
Capital contributions	286
Distributions	(74)
Capitalized interest	7
Equity income (loss), net	47
Equity method interest, ending balance	1,524
Altus Midstream Company | Gulf Coast Express Pipeline LLC
Movement In Equity Method Interests [Roll Forward]
Equity method interest, beginning balance	291
Capital contributions	1
Distributions	(39)
Capitalized interest	0
Equity income (loss), net	31
Equity method interest, ending balance	284
Altus Midstream Company | EPIC Crude Holdings, LP
Movement In Equity Method Interests [Roll Forward]
Equity method interest, beginning balance	163
Capital contributions	27
Distributions	0
Capitalized interest	0
Equity income (loss), net	(8)
Equity method interest, ending balance	182
Altus Midstream Company | Permian Highway Pipeline LLC
Movement In Equity Method Interests [Roll Forward]
Equity method interest, beginning balance	311
Capital contributions	258
Distributions	0
Capitalized interest	7
Equity income (loss), net	0
Equity method interest, ending balance	576
Altus Midstream Company | Breviloba, LLC
Movement In Equity Method Interests [Roll Forward]
Equity method interest, beginning balance	493
Capital contributions	0
Capitalized interest	0
Equity income (loss), net	24
Equity method interest, ending balance	$ 482

EQUITY METHOD INTERESTS - Sum_2

EQUITY METHOD INTERESTS - Summary of Combined Statement of Operations Equity Method Interests (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Schedule of Equity Method Investments [Line Items]
Operating revenues	$ 1,144	$ 1,500	$ 3,019	$ 4,775
Operating expenses	914	1,286	7,503	4,043
Operating income	206	182	(4,287)	719
Net income	41	(117)	$ (4,959)	$ (435)
Equity Method Investment, Nonconsolidated Investee or Group of Investees
Schedule of Equity Method Investments [Line Items]
Operating revenues	531	103
Operating expenses	264	62
Operating income	267	41
Net income	217	34
Other comprehensive loss	$ (1)	$ (11)

OTHER CURRENT LIABILITIES (Deta

OTHER CURRENT LIABILITIES (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Payables and Accruals [Abstract]
Accrued operating expenses	$ 99	$ 143
Accrued exploration and development	158	319
Accrued gathering, processing, and transmission - Altus	1	17
Accrued compensation and benefits	116	212
Accrued interest	111	135
Accrued income taxes	18	51
Current asset retirement obligation	47	47
Current operating lease liability	110	169
Current derivative liability	14	0
Other	129	56
Total Other current liabilities	$ 803	$ 1,149

ASSET RETIREMENT OBLIGATION (De

ASSET RETIREMENT OBLIGATION (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Asset retirement obligation at the beginning of period			$ 1,858
Liabilities incurred			10
Liabilities settled			(23)
Liabilities divested			(20)
Accretion expense	$ 27	$ 27	81	$ 80
Asset retirement obligation at the end of period	1,906		1,906
Less current portion	(47)		(47)		$ (47)
Asset retirement obligation, long-term	$ 1,859		$ 1,859		$ 1,811

DEBT AND FINANCING COSTS - Sche

DEBT AND FINANCING COSTS - Schedule of Debt (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Finance lease obligations	$ 37	$ 48
Unamortized discount	(35)	(42)
Debt issuance costs	(59)	(53)
Total debt	8,934	8,566
Current maturities	(184)	(11)
Long-term debt	8,750	8,555
Notes and debentures
Debt Instrument [Line Items]
Debt instrument, fair value	7,600	8,400
Notes and debentures | Unsecured Debt
Debt Instrument [Line Items]
Long-term debt, gross	8,324	8,217
Altus credit facility | Line of Credit
Debt Instrument [Line Items]
Long-term debt, gross	580	396
Apache credit facility | Line of Credit
Debt Instrument [Line Items]
Long-term debt, gross	$ 87	$ 0

DEBT AND FINANCING COSTS - Addi

DEBT AND FINANCING COSTS - Additional Information (Details) £ in Millions	Nov. 03, 2020	Aug. 18, 2020USD ($)	Mar. 31, 2019USD ($)	Nov. 30, 2018USD ($)contract	Sep. 30, 2020USD ($)	Jun. 30, 2020USD ($)	Sep. 30, 2019USD ($)	Sep. 30, 2020USD ($)	Sep. 30, 2019USD ($)	Sep. 30, 2020GBP (£)	Aug. 17, 2020USD ($)	Dec. 31, 2019USD ($)	Mar. 31, 2018USD ($)
Debt Instrument [Line Items]
Current debt outstanding amount					$ 184,000,000			$ 184,000,000				$ 11,000,000
Finance lease obligations, current					1,000,000			1,000,000				11,000,000
Gain on extinguishment of debt					12,000,000		$ 0	152,000,000	$ (75,000,000)
Commercial paper outstanding					0			0				0
Commercial Paper
Debt Instrument [Line Items]
Debt instrument, face amount					3,500,000,000			$ 3,500,000,000
Debt instrument term								270 days
Line of Credit | Revolving Credit Facility
Debt Instrument [Line Items]
Debt extension term				1 year
Senior Notes
Debt Instrument [Line Items]
Debt instrument, face amount											$ 1,250,000,000
Repurchased debt principal amount		$ 644,000,000			89,000,000	$ 410,000,000		$ 89,000,000
Discount to par of debt repurchase		38,000,000				147,000,000		11,000,000
Debt instrument, repurchase early tender premium		32,000,000
Debt repurchase, accrued and unpaid interest		6,000,000
Gain on extinguishment of debt		$ 2,000,000			10,000,000	140,000,000
Debt repurchase price					79,000,000	$ 267,000,000		79,000,000
3.625% senior notes due February 1, 2021 | Senior Notes
Debt Instrument [Line Items]
Current debt outstanding amount					$ 183,000,000			$ 183,000,000
Debt instrument, stated interest rate					3.625%			3.625%		3.625%
Altus credit facility | Line of Credit
Debt Instrument [Line Items]
Borrowing amount					$ 580,000,000			$ 580,000,000				396,000,000
Altus credit facility | Line of Credit | Revolving Credit Facility
Debt Instrument [Line Items]
Credit facility maximum borrowing capacity				$ 800,000,000
Letters of credit outstanding, amount					0			0				0
Line of credit facility, number of extension options | contract				2
Line of credit facility, maximum borrowing capacity if adding new lenders				$ 1,500,000,000
Long-term line of credit					580,000,000			580,000,000				396,000,000
Altus credit facility | Line of Credit | Letter of Credit
Debt Instrument [Line Items]
Credit facility maximum borrowing capacity				100,000,000
Altus credit facility | Line of Credit | Swingline Loan Subfacility
Debt Instrument [Line Items]
Credit facility maximum borrowing capacity				$ 100,000,000
4.625 Notes Due 2025 | Senior Notes
Debt Instrument [Line Items]
Debt instrument, stated interest rate											4.625%
Debt instrument, face amount											$ 500,000,000
4.875 Notes Due 2027 | Senior Notes
Debt Instrument [Line Items]
Debt instrument, stated interest rate											4.875%
Debt instrument, face amount											$ 750,000,000
Apache credit facility | Revolving Credit Facility
Debt Instrument [Line Items]
Line of credit facility, committed amount													$ 4,000,000,000
Debt extension term			1 year
Apache credit facility | Line of Credit
Debt Instrument [Line Items]
Borrowing amount					87,000,000			87,000,000				0
Apache credit facility | Line of Credit | Revolving Credit Facility
Debt Instrument [Line Items]
Credit facility maximum borrowing capacity			$ 5,000,000,000
Apache credit facility | Line of Credit | Letter of Credit
Debt Instrument [Line Items]
Line of credit facility, committed amount					$ 2,080,000,000			$ 2,080,000,000
Credit facility maximum borrowing capacity			$ 3,000,000,000
Letters of credit outstanding, amount										£ 637		$ 0
Subsequent Event | 3.625% senior notes due February 1, 2021 | Senior Notes
Debt Instrument [Line Items]
Redemption price, percentage of principal amount	100.00%

DEBT AND FINANCING COSTS - Comp

DEBT AND FINANCING COSTS - Components of Financing Costs, Net (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Debt Disclosure [Abstract]
Interest expense	$ 113	$ 107	$ 327	$ 323
Amortization of debt issuance costs	2	2	6	5
Capitalized interest	(3)	(9)	(9)	(26)
Loss (gain) on extinguishment of debt	12	0	152	(75)
Interest income	(1)	(5)	(4)	(12)
Financing costs, net	$ 99	$ 95	$ 168	$ 365

COMMITMENTS AND CONTINGENCIES (

COMMITMENTS AND CONTINGENCIES (Details) $ in Millions, $ in Millions	Sep. 10, 2020defendant	Sep. 11, 2019USD ($)plaintiff	Dec. 20, 2017Action	Jul. 17, 2017Actiondefendant	Dec. 31, 2017USD ($)	Sep. 30, 2020USD ($)	Sep. 30, 2020USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2013USD ($)	Apr. 30, 2017AUD ($)
Commitment And Contingencies [Line Items]
Accrued liability for legal contingencies						$ 69	$ 69
Undiscounted reserve for environmental remediation						2	2
Gulf Of Mexico Shelf Operations and Properties
Commitment And Contingencies [Line Items]
Percentage of net profits interest for funding trust account									10.00%
Gulf Of Mexico Shelf Operations and Properties | Disposed of by Sale
Commitment And Contingencies [Line Items]
Proceeds from sale of operations and properties									$ 3,750
discounted asset abandonment liabilities assumed									$ 1,500
Apollo Exploration Lawsuit
Commitment And Contingencies [Line Items]
Plaintiffs alleged damages							200	$ 1,100
Australian Operations Divestiture Dispute
Commitment And Contingencies [Line Items]
Plaintiffs alleged damages					$ 200
Gain contingency, unrecorded amount										$ 80
Canadian Operations Divestiture Dispute
Commitment And Contingencies [Line Items]
Plaintiffs alleged damages		$ 60
Number of plaintiffs | plaintiff		4
California Litigation
Commitment And Contingencies [Line Items]
Number of actions filed | Action			2	3
Number of defendants | defendant				30
Delaware Litigation
Commitment And Contingencies [Line Items]
Number of defendants | defendant	25
Castex Lawsuit
Commitment And Contingencies [Line Items]
Plaintiffs alleged damages						200
Loss contingency, estimated of possible loss amount						$ 60	60
Oklahoma Class Actions
Commitment And Contingencies [Line Items]
Plaintiffs alleged damages							$ 250

REDEMABLE NONCONTROLLING INTE_3

REDEMABLE NONCONTROLLING INTEREST - ALTUS - Additional Information (Details) - USD ($) $ in Millions	Jun. 12, 2019	Sep. 30, 2020	Sep. 30, 2019
Class of Stock [Line Items]
Redeemable noncontrolling interest - Altus Preferred Unit limited partners		$ 0	$ 611
Altus Midstream LP
Class of Stock [Line Items]
Embedded derivative	$ 94	$ 179
Altus Midstream LP | Altus Preferred Unit limited partners
Class of Stock [Line Items]
Aggregate issue price of Preferred Units	625
Redeemable noncontrolling interest - Altus Preferred Unit limited partners	611
Issue discount	4
Transaction costs	10
Embedded derivative	$ 94

REDEMABLE NONCONTROLLING INTE_4

REDEMABLE NONCONTROLLING INTEREST - ALTUS - Schedule of Preferred Units (Details) - Altus Midstream LP - USD ($) $ in Millions	Sep. 30, 2020	Jun. 12, 2019
Class of Stock [Line Items]
Preferred Units embedded derivative	$ 179	$ 94
Altus Preferred Unit limited partners
Class of Stock [Line Items]
Redeemable noncontrolling interest - Altus Preferred Unit limited partners		517
Preferred Units embedded derivative		94
Transaction price, net		$ 611

REDEMABLE NONCONTROLLING INTE_5

REDEMABLE NONCONTROLLING INTEREST - ALTUS - Activity Related to Preferred Units (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020USD ($)shares	Sep. 30, 2019USD ($)	Sep. 30, 2020USD ($)shares	Sep. 30, 2019USD ($)	Jun. 12, 2019USD ($)
Increase (Decrease) in Temporary Equity [Roll Forward]
Beginning balance			$ 555
Ending balance	$ 600		600
Altus Preferred Unit limited partners
Increase (Decrease) in Temporary Equity [Roll Forward]
Beginning balance	592	$ 521	555	$ 0
Allocation of Altus Midstream LP net income	19	18	56	22
Ending balance	600	$ 539	600	$ 539
Altus Midstream LP
Increase (Decrease) in Temporary Equity [Roll Forward]
Preferred Units embedded derivative	179		179		$ 94
Redeemable Noncontrolling Interest, Net Of Embedded Derivative Liability	$ 779		$ 779
Preferred units, redemption terms, internal rate of return	11.50%		11.50%
Preferred units, invested capital	$ 813		$ 813
Preferred units, redemption price	$ 709		$ 709
Altus Midstream LP | Altus Preferred Unit limited partners
Movement In Preferred Units [Roll Forward]
Preferred units: beginning of period (in shares) | shares			638,163
Distribution of in-kind additional preferred units (in shares) | shares			22,531
Preferred units: end of period (in shares) | shares	660,694		660,694
Increase (Decrease) in Temporary Equity [Roll Forward]
Beginning balance			$ 555
Distribution of in-kind additional Preferred Units			0
Cash distributions to Altus Preferred Unit limited partners			(11)
Allocation of Altus Midstream LP net income			56
Ending balance	$ 600		$ 600
Preferred Units embedded derivative					$ 94
Preferred units, redemption terms, multiple of invested capital	1.3		1.3

CAPITAL STOCK - Net Income (los

CAPITAL STOCK - Net Income (loss) Per Common Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Basic:
Loss attributable to common stock	$ (4)	$ (170)	$ (4,870)	$ (577)
Weighted average number of shares outstanding, basic (in shares)	378	377	378	377
Basic net income (loss) per share (in USD per share)	$ (0.01)	$ (0.45)	$ (12.89)	$ (1.53)
Effect of Dilutive Securities:
Redeemable noncontrolling interest - Altus Preferred Unit limited partners			$ 0	$ 0
Stock options and other (in shares)			0	0
Stock options and other (in USD per share)			$ 0	$ 0
Diluted:
Loss attributable to common stock	$ (8)	$ (170)	$ (4,870)	$ (577)
Loss attributable to common stock, shares	378	377	378	377
Diluted net income (loss) per share (in USD per share)	$ (0.02)	$ (0.45)	$ (12.89)	$ (1.53)
Altus Preferred Unit limited partners
Effect of Dilutive Securities:
Redeemable noncontrolling interest - Altus Preferred Unit limited partners	$ (4)	$ 0
Stock options and other (in shares)	0	0
Stock options and other (in USD per share)	$ (0.01)	$ 0
Stock Options and Other
Effect of Dilutive Securities:
Redeemable noncontrolling interest - Altus Preferred Unit limited partners	$ 0	$ 0
Stock options and other (in shares)	0	0
Stock options and other (in USD per share)	$ 0	$ 0

CAPITAL STOCK - Additional Info

CAPITAL STOCK - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	2 Months Ended	3 Months Ended		9 Months Ended		88 Months Ended
	Mar. 31, 2020	Mar. 12, 2020	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Dec. 31, 2018	Dec. 31, 2014
Equity [Abstract]
Options and restricted stock, anti-dilutive (in shares)			4,200,000	5,200,000	5,100,000	5,100,000
Payments of dividend on common stock			$ 9	$ 94	$ 113	$ 282
Common stock, dividends, per share (in USD per share)	$ 0.025	$ 0.25	$ 0.025	$ 0.25	$ 0.075	$ 0.75
Number of shares authorized to be repurchased (in shares)								40,000,000	40,000,000
Number of shares repurchased during period (in shares)					0		40,000,000
Average price of shares repurchased during period (in USD per share)							$ 79.18

BUSINESS SEGMENT INFORMATION (D

BUSINESS SEGMENT INFORMATION (Details)	3 Months Ended				9 Months Ended
	Sep. 30, 2020USD ($)	Jun. 30, 2020USD ($)	Mar. 31, 2020USD ($)	Sep. 30, 2019USD ($)	Sep. 30, 2020USD ($)Segment	Sep. 30, 2019USD ($)
Segment Reporting [Abstract]
Number of reporting segments | Segment					3
Segment Reporting Information [Line Items]
Lease operating expenses	$ 259,000,000			$ 350,000,000	$ 858,000,000	$ 1,104,000,000
Taxes other than income	34,000,000			44,000,000	90,000,000	141,000,000
Exploration	58,000,000			56,000,000	187,000,000	220,000,000
Depreciation, depletion, and amortization	398,000,000			711,000,000	1,382,000,000	1,959,000,000
Accretion expense	27,000,000			27,000,000	81,000,000	80,000,000
Impairments	0	$ 20,000,000	$ 4,500,000,000	9,000,000	4,492,000,000	249,000,000
Operating expenses	914,000,000			1,286,000,000	7,503,000,000	4,043,000,000
Operating Income (Loss)	206,000,000			182,000,000	(4,287,000,000)	719,000,000
Other Income (Expense):
Derivative instrument gains (losses), net	16,000,000			(2,000,000)	(262,000,000)	(40,000,000)
Gain (loss) on divestitures, net	(1,000,000)			0	24,000,000	20,000,000
Other, net	9,000,000			34,000,000	41,000,000	33,000,000
General and administrative	(52,000,000)			(98,000,000)	(214,000,000)	(323,000,000)
Transaction, reorganization, and separation	(7,000,000)			(7,000,000)	(44,000,000)	(17,000,000)
Financing costs, net	(99,000,000)			(95,000,000)	(168,000,000)	(365,000,000)
NET INCOME (LOSS) BEFORE INCOME TAXES	72,000,000			14,000,000	(4,910,000,000)	27,000,000
Total assets	12,875,000,000			21,405,000,000	12,875,000,000	21,405,000,000
Impairments	0			9,000,000	4,492,000,000	249,000,000
Operating Segments | Egypt
Segment Reporting Information [Line Items]
Lease operating expenses	102,000,000			115,000,000	312,000,000	365,000,000
Taxes other than income	0			0	0	0
Exploration	10,000,000			27,000,000	51,000,000	89,000,000
Depreciation, depletion, and amortization	144,000,000			177,000,000	463,000,000	538,000,000
Accretion expense	0			0	0	0
Impairments				0	529,000,000	0
Operating expenses	264,000,000			328,000,000	1,386,000,000	1,023,000,000
Operating Income (Loss)	115,000,000			218,000,000	(348,000,000)	718,000,000
Other Income (Expense):
Total assets	3,052,000,000			3,851,000,000	3,052,000,000	3,851,000,000
Impairments	2,000,000			2,000,000	535,000,000	6,000,000
Operating Segments | North Sea
Segment Reporting Information [Line Items]
Lease operating expenses	79,000,000			76,000,000	234,000,000	240,000,000
Taxes other than income	0			0	0	0
Exploration	10,000,000			0	26,000,000	2,000,000
Depreciation, depletion, and amortization	90,000,000			71,000,000	278,000,000	269,000,000
Accretion expense	18,000,000			19,000,000	54,000,000	56,000,000
Impairments				0	7,000,000	0
Operating expenses	207,000,000			175,000,000	636,000,000	599,000,000
Operating Income (Loss)	(10,000,000)			75,000,000	(4,000,000)	349,000,000
Other Income (Expense):
Total assets	2,238,000,000			2,529,000,000	2,238,000,000	2,529,000,000
Impairments					7,000,000
Operating Segments | U.S.
Segment Reporting Information [Line Items]
Lease operating expenses	79,000,000			159,000,000	313,000,000	501,000,000
Taxes other than income	30,000,000			41,000,000	79,000,000	131,000,000
Exploration	34,000,000			25,000,000	100,000,000	117,000,000
Depreciation, depletion, and amortization	161,000,000			452,000,000	632,000,000	1,125,000,000
Accretion expense	8,000,000			8,000,000	24,000,000	23,000,000
Impairments				0	3,956,000,000	240,000,000
Operating expenses	460,000,000			777,000,000	5,528,000,000	2,411,000,000
Operating Income (Loss)	83,000,000			(105,000,000)	(3,984,000,000)	(338,000,000)
Other Income (Expense):
Total assets	5,708,000,000			12,289,000,000	5,708,000,000	12,289,000,000
Impairments	34,000,000			10,000,000	4,000,000,000	308,000,000
Operating Segments | Altus Midstream
Segment Reporting Information [Line Items]
Lease operating expenses	0			0	0	0
Taxes other than income	4,000,000			3,000,000	11,000,000	10,000,000
Exploration	0			0	0	0
Depreciation, depletion, and amortization	3,000,000			11,000,000	9,000,000	27,000,000
Accretion expense	1,000,000			0	3,000,000	1,000,000
Impairments				9,000,000	0	9,000,000
Operating expenses	18,000,000			36,000,000	54,000,000	90,000,000
Operating Income (Loss)	22,000,000			(2,000,000)	59,000,000	2,000,000
Other Income (Expense):
Total assets	1,741,000,000			2,648,000,000	1,741,000,000	2,648,000,000
Impairments				9,000,000		9,000,000
Intersegment Eliminations & Other
Segment Reporting Information [Line Items]
Oil and gas production revenues	(39,000,000)			(34,000,000)	(111,000,000)	(92,000,000)
Lease operating expenses	(1,000,000)			0	(1,000,000)	(2,000,000)
Taxes other than income	0			0	0	0
Exploration	4,000,000			4,000,000	10,000,000	12,000,000
Depreciation, depletion, and amortization	0			0	0	0
Accretion expense	0			0	0	0
Impairments				0	0	0
Operating expenses	(35,000,000)			(30,000,000)	(101,000,000)	(80,000,000)
Operating Income (Loss)	(4,000,000)			(4,000,000)	(10,000,000)	(12,000,000)
Other Income (Expense):
Total assets	136,000,000			88,000,000	136,000,000	88,000,000
Intersegment Eliminations & Other | Altus Midstream
Segment Reporting Information [Line Items]
Oil and gas production revenues	(39,000,000)			(34,000,000)	(111,000,000)	(92,000,000)
Oil and gas
Segment Reporting Information [Line Items]
Oil and gas production revenues	1,120,000,000			1,468,000,000	3,216,000,000	4,762,000,000
Oil and gas | Operating Segments | Egypt
Segment Reporting Information [Line Items]
Oil and gas production revenues	379,000,000			546,000,000	1,038,000,000	1,741,000,000
Oil and gas | Operating Segments | North Sea
Segment Reporting Information [Line Items]
Oil and gas production revenues	197,000,000			250,000,000	632,000,000	948,000,000
Oil and gas | Operating Segments | U.S.
Segment Reporting Information [Line Items]
Oil and gas production revenues	543,000,000			672,000,000	1,544,000,000	2,073,000,000
Oil and gas | Operating Segments | Altus Midstream
Segment Reporting Information [Line Items]
Oil and gas production revenues	40,000,000			34,000,000	113,000,000	92,000,000
Oil and gas | Intersegment Eliminations & Other
Segment Reporting Information [Line Items]
Oil and gas production revenues	(39,000,000)			(34,000,000)	(111,000,000)	(92,000,000)
Oil and gas, excluding purchased
Segment Reporting Information [Line Items]
Oil and gas production revenues	1,046,000,000			1,438,000,000	2,979,000,000	4,690,000,000
Cost of oil and gas purchased	63,000,000			66,000,000	206,000,000	230,000,000
Oil and gas, excluding purchased | Operating Segments | Egypt
Segment Reporting Information [Line Items]
Oil and gas production revenues	379,000,000			546,000,000	1,038,000,000	1,741,000,000
Cost of oil and gas purchased	8,000,000			9,000,000	31,000,000	31,000,000
Oil and gas, excluding purchased | Operating Segments | North Sea
Segment Reporting Information [Line Items]
Oil and gas production revenues	197,000,000			250,000,000	632,000,000	948,000,000
Cost of oil and gas purchased	10,000,000			9,000,000	37,000,000	32,000,000
Oil and gas, excluding purchased | Operating Segments | U.S.
Segment Reporting Information [Line Items]
Oil and gas production revenues	470,000,000			642,000,000	1,309,000,000	2,001,000,000
Cost of oil and gas purchased	74,000,000			69,000,000	219,000,000	214,000,000
Oil and gas, excluding purchased | Operating Segments | Altus Midstream
Segment Reporting Information [Line Items]
Oil and gas production revenues	0			0	0	0
Cost of oil and gas purchased	9,000,000			13,000,000	29,000,000	43,000,000
Oil and gas, excluding purchased | Intersegment Eliminations & Other
Segment Reporting Information [Line Items]
Cost of oil and gas purchased	(38,000,000)			(34,000,000)	(110,000,000)	(90,000,000)
Oil and gas, purchased
Segment Reporting Information [Line Items]
Oil and gas production revenues	74,000,000			30,000,000	237,000,000	72,000,000
Cost of oil and gas purchased	75,000,000			23,000,000	207,000,000	60,000,000
Oil and gas, purchased | Operating Segments | Egypt
Segment Reporting Information [Line Items]
Oil and gas production revenues	0			0	0	0
Cost of oil and gas purchased	0			0	0	0
Oil and gas, purchased | Operating Segments | North Sea
Segment Reporting Information [Line Items]
Oil and gas production revenues	0			0	0	0
Cost of oil and gas purchased	0			0	0	0
Oil and gas, purchased | Operating Segments | U.S.
Segment Reporting Information [Line Items]
Oil and gas production revenues	73,000,000			30,000,000	235,000,000	72,000,000
Cost of oil and gas purchased	74,000,000			23,000,000	205,000,000	60,000,000
Oil and gas, purchased | Operating Segments | Altus Midstream
Segment Reporting Information [Line Items]
Oil and gas production revenues	1,000,000			0	2,000,000	0
Cost of oil and gas purchased	1,000,000			0	2,000,000	0
Oil and gas, purchased | Intersegment Eliminations & Other
Segment Reporting Information [Line Items]
Oil and gas production revenues	0			0	0	0
Cost of oil and gas purchased	0			0	0	0
Oil
Other Income (Expense):
Revenues from non-customer	38,000,000			98,000,000	65,000,000	316,000,000
Oil | Oil and gas, excluding purchased
Segment Reporting Information [Line Items]
Oil and gas production revenues	785,000,000			1,207,000,000	2,330,000,000	3,914,000,000
Oil | Oil and gas, excluding purchased | Operating Segments | Egypt
Segment Reporting Information [Line Items]
Oil and gas production revenues	303,000,000			472,000,000	823,000,000	1,509,000,000
Oil | Oil and gas, excluding purchased | Operating Segments | North Sea
Segment Reporting Information [Line Items]
Oil and gas production revenues	179,000,000			231,000,000	578,000,000	868,000,000
Oil | Oil and gas, excluding purchased | Operating Segments | U.S.
Segment Reporting Information [Line Items]
Oil and gas production revenues	303,000,000			504,000,000	929,000,000	1,537,000,000
Oil | Oil and gas, excluding purchased | Operating Segments | Altus Midstream
Segment Reporting Information [Line Items]
Oil and gas production revenues	0			0	0	0
Oil | Oil and gas, excluding purchased | Intersegment Eliminations & Other
Segment Reporting Information [Line Items]
Oil and gas production revenues	0			0	0	0
Natural Gas
Other Income (Expense):
Revenues from non-customer	6,000,000			9,000,000	9,000,000	30,000,000
Natural Gas | Oil and gas, excluding purchased
Segment Reporting Information [Line Items]
Oil and gas production revenues	164,000,000			136,000,000	417,000,000	490,000,000
Natural Gas | Oil and gas, excluding purchased | Operating Segments | Egypt
Segment Reporting Information [Line Items]
Oil and gas production revenues	74,000,000			72,000,000	209,000,000	223,000,000
Natural Gas | Oil and gas, excluding purchased | Operating Segments | North Sea
Segment Reporting Information [Line Items]
Oil and gas production revenues	13,000,000			14,000,000	39,000,000	64,000,000
Natural Gas | Oil and gas, excluding purchased | Operating Segments | U.S.
Segment Reporting Information [Line Items]
Oil and gas production revenues	77,000,000			50,000,000	169,000,000	203,000,000
Natural Gas | Oil and gas, excluding purchased | Operating Segments | Altus Midstream
Segment Reporting Information [Line Items]
Oil and gas production revenues	0			0	0	0
Natural Gas | Oil and gas, excluding purchased | Intersegment Eliminations & Other
Segment Reporting Information [Line Items]
Oil and gas production revenues	0			0	0	0
Natural Gas liquids
Other Income (Expense):
Revenues from non-customer	0			0	0	1,000,000
Natural Gas liquids | Oil and gas, excluding purchased
Segment Reporting Information [Line Items]
Oil and gas production revenues	97,000,000			95,000,000	232,000,000	286,000,000
Natural Gas liquids | Oil and gas, excluding purchased | Operating Segments | Egypt
Segment Reporting Information [Line Items]
Oil and gas production revenues	2,000,000			2,000,000	6,000,000	9,000,000
Natural Gas liquids | Oil and gas, excluding purchased | Operating Segments | North Sea
Segment Reporting Information [Line Items]
Oil and gas production revenues	5,000,000			5,000,000	15,000,000	16,000,000
Natural Gas liquids | Oil and gas, excluding purchased | Operating Segments | U.S.
Segment Reporting Information [Line Items]
Oil and gas production revenues	90,000,000			88,000,000	211,000,000	261,000,000
Natural Gas liquids | Oil and gas, excluding purchased | Operating Segments | Altus Midstream
Segment Reporting Information [Line Items]
Oil and gas production revenues	0			0	0	0
Natural Gas liquids | Oil and gas, excluding purchased | Intersegment Eliminations & Other
Segment Reporting Information [Line Items]
Oil and gas production revenues	$ 0			$ 0	$ 0	$ 0