Loan Sale and Servicing Activities and Variable Interest Entities (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Liability related to investments in low income housing tax credits	$ 2,000	$ 1,100
Low Income Housing Tax Credit Investments
Amortization Recognized Low Income Housing Tax Credit Investments	300
Tax Credits Recognized Low Income Housing Tax Credit Investments	300
Other tax benefits associated with qualified investments in low income housing tax credits (less than)	$ 100