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)	APA SHAREHOLDERS’ EQUITY (DEFICIT)	Noncontrolling Interests	Noncontrolling interests, Egypt	Noncontrolling interests, Altus	Altus Preferred Unit limited partners
Beginning balance at Dec. 31, 2019											$ 555
Increase (Decrease) In Redeemable Noncontrolling Interest [Roll Forward]
Net income attributable to Altus Preferred Unit limited partners											18
Distributions to noncontrolling interest	$ (32)							$ (32)
Ending balance at Mar. 31, 2020											573
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 income (loss) attributable to common stock	(4,480)			(4,480)			(4,480)
Net income (loss) attributable to noncontrolling interest									$ (151)	$ (9)	18
Distributions to noncontrolling interest - Egypt	(32)							(32)
Common dividends	(10)		(10)				(10)
Other	(11)	1	(12)		1	(1)	(11)
Ending balance at Mar. 31, 2020	(228)	262	11,747	(10,081)	(3,189)	15	(1,246)	1,018
Beginning balance at Dec. 31, 2019											555
Ending balance at Dec. 31, 2020	608										608
Beginning balance at Dec. 31, 2019	4,465	261	11,769	(5,601)	(3,190)	16	3,255	1,210
Ending balance at Dec. 31, 2020	(645)	262	11,735	(10,461)	(3,189)	14	(1,639)	994
Increase (Decrease) In Redeemable Noncontrolling Interest [Roll Forward]
Net income attributable to Altus Preferred Unit limited partners											19
Distributions payable to Altus Preferred Unit limited partners											(11)
Distributions to noncontrolling interest	(40)							(40)			(11)
Ending balance at Mar. 31, 2021	605										605
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss) attributable to common stock	388			388			388
Net income (loss) attributable to noncontrolling interest	42								$ 42	$ 1	19
Distributions to noncontrolling interest - Egypt	(40)							(40)			$ (11)
Common dividends	(9)		(9)				(9)
Other	2		1			1	2
Ending balance at Mar. 31, 2021	$ (261)	$ 262	$ 11,727	$ (10,073)	$ (3,189)	$ 15	$ (1,258)	$ 997