Derivative Instruments (Details 1) - Derivatives not designated as hedging instruments: - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Gains (losses) on derivatives financial instruments included in the Consolidated Statements of Income
Gains (losses) on derivative financial instruments	$ (152)	$ 4,566	$ (247)
Included in interest income on loans | Interest rate contracts
Gains (losses) on derivatives financial instruments included in the Consolidated Statements of Income
Gains (losses) on derivative financial instruments	3,981	2,402	2,200
Included in mortgage banking income | Interest rate lock commitments
Gains (losses) on derivatives financial instruments included in the Consolidated Statements of Income
Gains (losses) on derivative financial instruments	356	(2,111)	(530)
Included in mortgage banking income | Forward commitments
Gains (losses) on derivatives financial instruments included in the Consolidated Statements of Income
Gains (losses) on derivative financial instruments	$ (4,489)	$ 4,275	$ (1,917)