Deposits (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Loans and Leases Receivable Disclosure [Line Items]
Time deposits, at $250,000 or more	$ 35,150	$ 46,400
Demand deposit overdrafts	3,260	5,440
Non-U.S.
Loans and Leases Receivable Disclosure [Line Items]
Time deposits, at $250,000 or more	139	314
Wholesale CDs
Loans and Leases Receivable Disclosure [Line Items]
Time deposits, at $250,000 or more	3,000	4,520
Customer Deposits
Loans and Leases Receivable Disclosure [Line Items]
Time deposits, at $250,000 or more	$ 32,010	$ 41,570