Loan Sale and Servicing Activities and Variable Interest Entities (Loan Sale and Servicing Activities and Variable Interest Entities) (Narrative) (Details) - Low Income Housing Tax Credit And Market Tax Credit - USD ($) $ in Billions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortization recognized	$ 0.1	$ 0.1
Tax credits	0.2	0.1
Other tax benefits (less than in all periods)	$ 0.1	$ 0.1