Premises and Equipment (Details Textuals) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Abstract]
Depreciation and amortization	$ 33	$ 34	$ 33
Rental expense under leases	$ 13	$ 11	$ 13