Employee Benefits and Other Expenses, Other Expenses (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Defined Benefit Plan Disclosure [Line Items]
Other noninterest expense	$ 938	$ 1,113
Regulatory charges and assessments expense, including FDIC assessment expense [Member]
Defined Benefit Plan Disclosure [Line Items]
Other noninterest expense	$ 225	$ 217