Premises and Equipment (Details Textuals) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Depreciation and amortization	$ 32	$ 33	$ 34
Rental expense under leases	8	$ 13	$ 11
Milwaukee Center
Property, Plant and Equipment [Line Items]
Leasing income	$ 4