Consolidated Statements of Stockholders' Equity - USD ($) $ in Millions	Total	Preferred Stock	Common Stock	Treasury Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Non-controlling Interests
Beginning balance at Dec. 31, 2017	$ 20,572	$ 0	$ 179	$ (9,168)	$ 7,884	$ 21,935	$ (258)	$ 0
Increase (Decrease) in Stockholders' Equity
Net income (loss)	4,131					4,131
Other comprehensive income (loss), net of tax	144						144
Dividends on common stock	(2,374)					(2,374)
Issuance of common stock and other, net	162				162
Purchases of treasury stock	(1,305)			(1,305)
Reclassification of stranded tax effects	0					58	(58)
Ending balance at Dec. 31, 2018	21,330	0	179	(10,473)	8,046	23,750	(172)	0
Increase (Decrease) in Stockholders' Equity
Net income (loss)	(522)					(667)		145
Other comprehensive income (loss), net of tax	(49)						(49)
Dividends on common stock	(2,585)					(2,585)
Dividends on preferred stock	(318)					(318)
Issuance of common stock and other, net	6,939		30		6,909
Issuance of preferred stock	9,762	9,762
Purchases of treasury stock	(180)			(180)
Fair value of noncontrolling interest acquired	4,895							4,895
Noncontrolling interest distributions, net	(131)							(131)
Change in control WES	(4,909)							(4,909)
Ending balance at Dec. 31, 2019	34,232	9,762	209	(10,653)	14,955	20,180	(221)	0
Increase (Decrease) in Stockholders' Equity
Net income (loss)	(14,831)					(14,831)
Other comprehensive income (loss), net of tax	(67)						(67)
Dividends on common stock	(746)					(746)
Dividends on preferred stock	(400)		6		438	(844)
Issuance of warrants on common stock	4				767	(763)
Berkshire Warrants	103				103
Issuance of common stock and other, net	290		1		289
Purchases of treasury stock	(12)			(12)
Ending balance at Dec. 31, 2020	$ 18,573	$ 9,762	$ 216	$ (10,665)	$ 16,552	$ 2,996	$ (288)	$ 0