Variable Interest Entities (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Non Interest Expenses
Variable Interest Entity [Line Items]
Losses from LIHC investments included in other noninterest expense	$ 8	$ 15	$ 11
Income Tax Expense
Variable Interest Entity [Line Items]
Amortization of LIHC investments included in income tax expense	129	118	116
Tax credits and other tax benefits from LIHC investments included in income tax expense	$ 188	$ 175	$ 164