Securities, Gains (Loss) on Sales of Securities, Securities Pledged, and Securities Sold Under Agreements to Repurchase (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Securities [Abstract]
Net gains realized on sales of AFS securities	$ 68	$ 144
Amortized cost of securities pledged as collateral to secure public deposit and for other purposes	188,100		$ 228,200
Amortized cost of securities sold under agreements to repurchase	$ 287,200		$ 285,500