Loan Sale and Servicing Activities and Variable Interest Entities (Loan Sale and Servicing Activities and Variable Interest Entities) (Narrative) (Details) - Variable Interest Entity, Primary Beneficiary - USD ($) $ in Billions	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Accounts, Notes, Loans and Financing Receivable [Line Items]
Investment Program, Proportional Amortization Method, Applied, Amortization Expense	$ 0.4	$ 0.3
Low Income Housing Tax Credit And Market Tax Credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Tax credits	0.4	0.3
Other tax benefits (less than in current period)	$ 0.1	$ 0.1