Income Taxes (Schedule of Tax Effects of Deferred Tax Assets and Deferred Tax Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Gross deferred tax assets:
Book loan loss deduction in excess of tax	$ 181	$ 157
Deferred compensation	81	83
Security investments and derivative fair value adjustments	879	1,011
Lease liabilities	50	49
Capitalized costs	37	82
Other	48	29
Total deferred tax assets before valuation allowance	1,276	1,411
Valuation allowance	0	0
Total deferred tax assets	1,276	1,411
Gross deferred tax liabilities:
Premises and equipment, due to differences in depreciation	(101)	(99)
Federal Home Loan Bank stock dividends	(3)	(2)
Leasing operations	(49)	(49)
Prepaid expenses	(5)	(5)
Prepaid pension reserves	0	(3)
Mortgage servicing	(5)	(12)
Deferred loan costs	(34)	(34)
ROU assets	(43)	(44)
Qualified opportunity fund deferred gains	(27)	(26)
Equity investments	(10)	(9)
Total deferred tax liabilities	(277)	(283)
Net deferred tax assets (liabilities)	$ 999	$ 1,128