Earnings Per Share and Stockholders' Equity - Schedule of Basic and Diluted Net Income (Loss) Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Basic earnings (loss) per common share
Net income (loss) from continuing operations	$ 830	$ (3,655)	$ 1,229	$ (12,384)
Income (loss) from discontinued operations, net of tax	(2)	80	(444)	(1,335)
NET INCOME (LOSS)	828	(3,575)	785	(13,719)
Less: Preferred stock dividends	(200)	(203)	(600)	(644)
NET INCOME (LOSS) ATTRIBUTABLE TO COMMON STOCKHOLDERS	628	(3,778)	185	(14,363)
Less: Net income allocated to participating securities	(5)	0	(1)	0
Net income (loss), net of participating securities	$ 623	$ (3,778)	$ 184	$ (14,363)
Weighted-average number of basic shares (in shares)	935.4	929.3	934.4	913.9
Basic income (loss) per common share (in dollars per share)	$ 0.67	$ (4.07)	$ 0.20	$ (15.72)
Dilutive securities (in shares)	22.3	0.0	19.8	0.0
Total dilutive weighted-average common shares (in shares)	957.7	929.3	954.2	913.9
Diluted income (loss) per common share (in dollars per share)	$ 0.65	$ (4.07)	$ 0.19	$ (15.72)