Loan Sale and Servicing Activities and Variable Interest Entities Loan Sale and Servicing Activities and Variable Interest Entities (Narrative) (Details) - USD ($) $ in Billions	9 Months Ended
Sep. 30, 2021	Sep. 30, 2020
Low Income Housing Tax Credit Investments
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortization, tax credits, and other tax benefits recognized low income housing tax credit investments (less than)	$ 0.1	$ 0.1

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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