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		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Earnings Per Share:
Net income available to common shareholders	$ 526	$ 674	$ 1,000	$ 1,348
Less: Income allocated to participating securities	1	1	1	4
Net income allocated to common shareholders	$ 525	$ 673	$ 999	$ 1,344
Average shares	689,018,541	708,832,787	688,282,355	711,617,331
Earnings per share (in dollars per share)	$ 0.76	$ 0.95	$ 1.45	$ 1.89
Earnings Per Diluted Share:
Net income available to common shareholders	$ 526	$ 674	$ 1,000	$ 1,348
Stock-based awards	0	0	0	0
Less: Income allocated to participating securities	1	1	1	4
Net income allocated to common shareholders	$ 525	$ 673	$ 999	$ 1,344
Average shares, stock based awards	6,000,000	9,000,000	8,000,000	9,000,000
Average shares	694,804,715	718,084,745	695,519,583	720,740,176
Earnings per diluted share (in dollars per share)	$ 0.76	$ 0.94	$ 1.44	$ 1.87