Earnings Per Share - Calculation of Earnings Per Share and the Reconciliation of Earnings Per Share to Earnings Per Diluted Share (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Earnings Per Share:
Net income available to common shareholders	$ 474	$ 674
Less: Income allocated to participating securities	1	2
Net income allocated to common shareholders	$ 473	$ 672
Average shares	687,537,989	714,432,813
Earnings per share (in dollars per share)	$ 0.69	$ 0.94
Earnings Per Diluted Share:
Net income available to common shareholders	$ 474	$ 674
Stock-based awards	0	0
Less: Income allocated to participating securities	1	2
Net income allocated to common shareholders	$ 473	$ 672
Average shares, stock based awards	8,000,000	9,000,000
Average shares	696,242,395	723,425,111
Earnings per diluted share (in dollars per share)	$ 0.68	$ 0.93