Variable Interest Entities Variable Interest Entities (Details 3) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Other Non Interest Expenses
Noncontrolling Interest [Line Items]
Income (loss) from LIHC Investments	$ 2	$ 1	$ 4	$ 3
Income Tax Expense
Noncontrolling Interest [Line Items]
Amortization of LIHC investments	36	32	69	62
Tax credits and other tax benefits from LIHC	$ 47	$ 47	$ 92	$ 92