STATEMENT OF CONSOLIDATED CHANGES IN EQUITY (DEFICIT) AND NONCONTROLLING INTEREST (Unaudited) - USD ($) $ in Millions	Total	Noncontrolling interests, Egypt	Noncontrolling interests, Altus	APA SHAREHOLDERS’ DEFICIT	Common Stock	Paid-In Capital	Accumulated Deficit	Treasury Stock	Accumulated Other Comprehensive Income	Noncontrolling Interests	Noncontrolling Interests Noncontrolling interests, Egypt	Noncontrolling Interests Noncontrolling interests, Altus
Beginning balance at Dec. 31, 2019	$ 555
Increase (Decrease) in Temporary Equity [Roll Forward]
Net income attributable to Altus Preferred Unit limited partners	56
Distributions payable to Altus Preferred Unit limited partners	(11)
Distributions to noncontrolling interest		$ (61)									$ (61)
Ending balance at Sep. 30, 2020	600
Beginning balance at Dec. 31, 2019	4,465			$ 3,255	$ 261	$ 11,769	$ (5,601)	$ (3,190)	$ 16	$ 1,210
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss) attributable to common stock	(4,870)			(4,870)			(4,870)
Net income (loss) attributable to noncontrolling interest		(138)	$ (7)								(138)	$ (7)
Distributions to noncontrolling interest - Egypt		(61)									(61)
Common dividends	(29)			(29)		(29)
Other	3			3	1	1		1
Ending balance at Sep. 30, 2020	(637)			(1,641)	262	11,741	(10,471)	(3,189)	16	1,004
Beginning balance at Jun. 30, 2020	592
Increase (Decrease) in Temporary Equity [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		(21)									(21)
Ending balance at Sep. 30, 2020	600
Beginning balance at Jun. 30, 2020	(636)			(1,635)	262	11,744	(10,467)	(3,189)	15	999
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss) attributable to common stock	(4)			(4)			(4)
Net income (loss) attributable to noncontrolling interest		24	2								24	2
Distributions to noncontrolling interest - Egypt		(21)									(21)
Common dividends	(10)			(10)		(10)
Other	8			8		7			1
Ending balance at Sep. 30, 2020	(637)			(1,641)	262	11,741	(10,471)	(3,189)	16	1,004
Beginning balance at Dec. 31, 2020	608
Increase (Decrease) in Temporary Equity [Roll Forward]
Net income attributable to Altus Preferred Unit limited partners	73
Distributions payable to Altus Preferred Unit limited partners	(12)
Distributions to noncontrolling interest	(34)	(203)									(203)
Ending balance at Sep. 30, 2021	635
Beginning balance at Dec. 31, 2020	(645)			(1,639)	262	11,735	(10,461)	(3,189)	14	994
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss) attributable to common stock	591			591			591
Net income (loss) attributable to noncontrolling interest		132	32								132	32
Distributions to noncontrolling interest - Egypt	(34)	(203)									(203)
Common dividends	(43)			(43)		(43)
Other	(14)			(4)		(6)		1	1	(10)
Ending balance at Sep. 30, 2021	(150)			(1,095)	262	11,686	(9,870)	(3,188)	15	945
Beginning balance at Jun. 30, 2021	617
Increase (Decrease) in Temporary Equity [Roll Forward]
Net income attributable to Altus Preferred Unit limited partners	30
Distributions payable to Altus Preferred Unit limited partners	(12)
Distributions to noncontrolling interest		(143)									(143)
Ending balance at Sep. 30, 2021	635
Beginning balance at Jun. 30, 2021	76			(964)	262	11,704	(9,757)	(3,188)	15	1,040
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss) attributable to common stock	(113)			(113)			(113)
Net income (loss) attributable to noncontrolling interest		49	$ 4								49	$ 4
Distributions to noncontrolling interest - Egypt		$ (143)									$ (143)
Common dividends	(24)			(24)		(24)
Other	1			6		6				(5)
Ending balance at Sep. 30, 2021	$ (150)			$ (1,095)	$ 262	$ 11,686	$ (9,870)	$ (3,188)	$ 15	$ 945