Income (loss) and Dividends per Common Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Earnings Per Share [Abstract]
Antidilutive securities excluded from computation of earnings per share (in shares)	4	7	6
Net income (loss)	$ 946	$ (1,451)	$ 480
Weighted average common shares outstanding (in shares)	787	792	810
Effect of dilutive securities (in shares)	1	0	0
Weighted average common shares, diluted (in shares)	788	792	810
Basic (in dollars per share)	$ 1.20	$ (1.83)	$ 0.59
Diluted (in dollars per share)	1.20	(1.83)	0.59
Dividends paid (in dollars per share)	$ 0.18	$ 0.08	$ 0.20