Derivative Financial Instruments (Other free standing derivatives) (Gains (losses) recognized) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Net gains on sale of loans held for sale | Interest rate lock commitments (mortgage)
Trading Activity, Gains and Losses, Net [Line Items]
Gain (Loss) Recognized	$ 17	$ 1,062
Net gains on sale of loans held for sale | Forward commitments
Trading Activity, Gains and Losses, Net [Line Items]
Gain (Loss) Recognized	115	(2,739)
Other noninterest income | Undesignated interest rate swaps
Trading Activity, Gains and Losses, Net [Line Items]
Gain (Loss) Recognized	$ 277	$ 117