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, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Earnings Per Share:
Net income available to common shareholders	$ 562	$ 526	$ 1,097	$ 1,000
Less: Income allocated to participating securities	0	1	0	1
Net income allocated to common shareholders	$ 562	$ 525	$ 1,097	$ 999
Average shares (in shares)	684,028,603	689,018,541	684,023,063	688,282,355
Earnings per share (in dollars per share)	$ 0.82	$ 0.76	$ 1.60	$ 1.45
Earnings Per Diluted Share:
Net income available to common shareholders	$ 562	$ 526	$ 1,097	$ 1,000
Stock-based awards	0	0	0	0
Less: Income allocated to participating securities	0	1	0	1
Net income allocated to common shareholders	$ 562	$ 525	$ 1,097	$ 999
Average shares, stock based awards (in shares)	2,000,000	6,000,000	4,000,000	8,000,000
Average shares (in shares)	686,385,938	694,804,715	687,967,395	695,519,583
Earnings per diluted share (in dollars per share)	$ 0.82	$ 0.76	$ 1.59	$ 1.44