Medium- And Long-Term Debt (Schedule Of Medium- And Long-Term Debt) (Details) - USD ($) $ in Millions	6 Months Ended
Jun. 30, 2024	Dec. 31, 2023
Debt Instrument [Line Items]
Medium- and long-term debt	$ 7,112	$ 6,206
Parent company
Debt Instrument [Line Items]
Medium- and long-term notes	1,491	523
Medium- and long-term debt	1,730	764
Subsidiaries
Debt Instrument [Line Items]
Subordinated notes	946	965
Total FHLB advances:	3,937	3,988
Medium- and long-term debt	5,382	5,442
3.80% subordinated notes due 2026 \| Parent company
Debt Instrument [Line Items]
Subordinated notes	$ 239	241
Stated interest rate	3.80%
Maturity year	2026
4.00% notes due 2029 \| Parent company
Debt Instrument [Line Items]
Medium- and long-term notes	$ 513	523
Stated interest rate	4.00%
Maturity year	2029
5.982% Notes Due 2030 \| Parent company
Debt Instrument [Line Items]
Medium- and long-term notes	$ 978	0
Stated interest rate	5.982%
4.00% subordinated notes due 2025 \| Subsidiaries
Debt Instrument [Line Items]
Subordinated notes	$ 339	337
Stated interest rate	4.00%
Maturity year	2025
7.875% subordinated notes due 2026 \| Subsidiaries
Debt Instrument [Line Items]
Subordinated notes	$ 157	162
Stated interest rate	7.875%
5.332 subordinated notes due 2033 \| Subsidiaries
Debt Instrument [Line Items]
Subordinated notes	$ 450	466
Stated interest rate	5.332%
Maturity year	2033
2.50% notes due 2024 \| Subsidiaries
Debt Instrument [Line Items]
Medium- and long-term notes	$ 499	489
Stated interest rate	2.50%
Maturity year	2024
5.07% advance due 2025 \| Subsidiaries
Debt Instrument [Line Items]
Total FHLB advances:	$ 993	995
Stated interest rate	5.07%
Maturity year	2025
4.79% advance due 2026 \| Subsidiaries
Debt Instrument [Line Items]
Total FHLB advances:	$ 986	997
Stated interest rate	4.79%
Maturity year	2026
4.49% advance due 2027 \| Subsidiaries
Debt Instrument [Line Items]
Total FHLB advances:	$ 982	999
Stated interest rate	4.49%
Maturity year	2027
4.49% advance due 2028 \| Subsidiaries
Debt Instrument [Line Items]
Total FHLB advances:	$ 976	$ 997
Stated interest rate	4.49%
Maturity year	2028

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