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Medium- And Long-Term Debt (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Debt Instrument [Line Items]
Fixed-to-floating rate subordinated notes	$ 500
Fair value fixed-to-floating rate swap	2.67%
Unamortized debt issuance costs	$ 9	$ 7
Subsidiaries
Debt Instrument [Line Items]
Long-term Federal Home Loan Bank advances	$ 0	$ 0
5.332% subordinated notes due 2033 | Subsidiaries
Debt Instrument [Line Items]
Debt Instrument, Maturity Year	2033
Stated interest rate	5.332%

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

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Including both current and noncurrent portions, Federal Home Loan Bank borrowings initially due beyond one year or beyond the normal operating cycle if longer.

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