Deposits - Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Loans and Leases Receivable Disclosure [Line Items]
Domestic deposits of $100,000 or more	$ 55,030	$ 46,550
Non-U.S.
Loans and Leases Receivable Disclosure [Line Items]
Domestic deposits of $100,000 or more	$ 214	$ 127