Computation of Earnings per Common Share - Computation of Basic and Diluted EPS (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Earnings Per Share [Abstract]
Net income available to common shareholders	$ 144	$ 140	$ 453	$ 421
Less: Dividends paid on and earnings allocated to participating securities	(2)	(2)	(6)	(5)
Earnings applicable to common stock	$ 142	$ 138	$ 447	$ 416
Weighted average common shares outstanding	465,115,180	464,047,337	465,354,754	463,813,827
Basic earnings per common share	$ 0.31	$ 0.30	$ 0.96	$ 0.90
Earnings applicable to common stock	$ 142	$ 138	$ 447	$ 416
Potential dilutive common shares	979,177	834,612	926,184	744,292
Total shares for diluted earnings per common share computation	466,094,357	464,881,949	466,280,938	464,558,119
Diluted earnings per common share and common share equivalents	$ 0.30	$ 0.30	$ 0.96	$ 0.90