Derivative and Hedging Activities, Income Statement Category of the Gains and Losses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Capital market fees, net | Interest rate-related instruments — customer and mirror
Gain (loss) on derivative instruments not designated as hedging instruments
Gain / (Loss) Recognized in Income	$ (24)	$ 1,978
Capital market fees, net | Foreign currency exchange forwards
Gain (loss) on derivative instruments not designated as hedging instruments
Gain / (Loss) Recognized in Income	97	(75)
Capital market fees, net | Commodity contracts
Gain (loss) on derivative instruments not designated as hedging instruments
Gain / (Loss) Recognized in Income	647	630
Mortgage banking, net | Interest rate lock commitments (mortgage)
Gain (loss) on derivative instruments not designated as hedging instruments
Gain / (Loss) Recognized in Income	1,332	(752)
Mortgage banking, net | Forward commitments (mortgage)
Gain (loss) on derivative instruments not designated as hedging instruments
Gain / (Loss) Recognized in Income	$ (3,221)	$ 2,505