Variable Interest Entities Variable Interest Entities (Details 3) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Other Non Interest Expenses
Noncontrolling Interest [Line Items]
Income (loss) from LIHC Investments	$ 5	$ 4	$ 9	$ 9
Income Tax Expense
Noncontrolling Interest [Line Items]
Amortization of LIHC investments	28	30	84	85
Tax credits and other tax benefits from LIHC	$ 46	$ 41	$ 136	$ 119