Variable Interest Entities Variable Interest Entities (Details 3) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Other Non Interest Expenses
Noncontrolling Interest [Line Items]
Income (loss) from LIHC Investments	$ 2	$ 2
Income Tax Expense
Noncontrolling Interest [Line Items]
Amortization of LIHC investments	33	30
Tax credits and other tax benefits from LIHC	$ 45	$ 45