Junior Subordinated Debt Securities (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Debt Instrument, Description of Variable Rate Basis	three-month LIBOR
Debt Instrument, Face Amount		$ 3,200
Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net	$ 82	90
Interest Expense, Junior Subordinated Debentures	261	261	$ 261
Senior notes
Debt Instrument [Line Items]
Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net	$ 77	85
Debt Instrument, Interest Rate, Stated Percentage	5.70%
Junior Subordinated Debt [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 3,200
Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net	44	47
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	$ 6	6
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	$ 16	17
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	$ 13	14
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	$ 9	$ 10
Debt Instrument, Interest Rate, Stated Percentage	9.25%

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Face (par) amount of debt instrument at time of issuance.

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Contractual interest rate for funds borrowed, under the debt agreement.

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Amount of unamortized debt discount (premium) and debt issuance costs.

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Interest expense incurred during the reporting period on junior subordinated debentures. Includes amortization of expenses incurred in the issuance of subordinated notes and debentures.

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