Goodwill and Other Intangible Assets Intangible Assets Schedule of Future Amortization (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2017	Mar. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Amortization of Intangible Assets	[1]	$ 5	$ 2
Other Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization of Intangible Assets	[1]	5	2
Mortgage Servicing Rights, Fair Value [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization of Intangible Assets	[1]	$ 0	$ 0

[1] Does not include expense associated with non-qualified community development investments. See Note 9, "Certain Transfers of Financial Assets and Variable Interest Entities," for additional information.