Condensed Financial Information (Parent Company) (Interest Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Interest Expense [Abstract]
Total interest expense	$ 655	$ 647	$ 632
Parent Company
Interest Expense [Abstract]
Total interest expense	829	847	833
Parent Company | Long-term Debt
Interest Expense [Abstract]
Total interest expense	583	590	570
Parent Company | Long-term Debt | Affiliated Entity
Interest Expense [Abstract]
Total interest expense	37	47	52
Parent Company | Secured Debt [Member]
Interest Expense [Abstract]
Total interest expense	4	5	6
Parent Company | Junior Subordinated Debt [Member]
Interest Expense [Abstract]
Total interest expense	$ 205	$ 205	$ 205