Deposits (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Loans and Leases Receivable Disclosure [Line Items]
Time deposits, at $250,000 or more	$ 1,680	$ 35,150
Demand deposit overdrafts	$ 2,980	3,260
Non-U.S.
Loans and Leases Receivable Disclosure [Line Items]
Time deposits, at $250,000 or more		139
Wholesale CDs
Loans and Leases Receivable Disclosure [Line Items]
Time deposits, at $250,000 or more		3,000
Customer Deposits
Loans and Leases Receivable Disclosure [Line Items]
Time deposits, at $250,000 or more		$ 32,010