Summary of Significant Accounting Policies and Other Matters - Earnings Per Common Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Accounting Policies [Abstract]
Net income for common stock	$ 255	$ 165	$ 857	$ 584
Weighted average common shares outstanding – basic (shares)	354.3	345.4	354.2	344.0
Add: Incremental shares attributable to effect of potentially dilutive securities (shares)	1.2	0.8	1.1	0.8
Adjusted weighted average common shares outstanding – diluted (shares)	355.5	346.2	355.3	344.8
Net income per common share - basic (dollars per share)	$ 0.72	$ 0.48	$ 2.42	$ 1.70
Net income per common share - diluted (dollars per share)	$ 0.72	$ 0.48	$ 2.41	$ 1.70