Junior Subordinated Debt Securities (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Debt Instrument [Line Items]
Debt Instrument, Description of Variable Rate Basis	three-month CME Term SOFR plus 0.26161%
Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net	$ 108	$ 87
Interest Expense, Junior Subordinated Debentures	261	261	$ 261
Senior notes
Debt Instrument [Line Items]
Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net	$ 106	83
Debt Instrument, Interest Rate, Stated Percentage	5.70%
Junior Subordinated Debt [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 3,200	3,200
Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net	39	42
Junior Subordinated Debt Instrument One [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	500	500
Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net	$ 5	5
Debt Instrument, Interest Rate, Stated Percentage	10.75%
Junior Subordinated Debt Instrument Four [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 1,250	1,250
Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net	$ 14	15
Debt Instrument, Interest Rate, Stated Percentage	6.40%
Junior Subordinated Debt Instrument Three [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 700	700
Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net	$ 12	13
Debt Instrument, Interest Rate, Stated Percentage	7.875%
Junior Subordinated Debt Instrument Two [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 750	750
Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net	$ 8	$ 9
Debt Instrument, Interest Rate, Stated Percentage	9.25%