CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 31,082	$ 41,311	$ 18,565
Unrealized gains and losses:
Unrealized holding (losses) gains on available-for-sale securities arising during the period	(5,624)	(2,991)	6,966
Tax effect	2,142	1,196	(2,635)
Net of tax	(3,482)	(1,795)	4,331
Unrealized gains on securities transferred from held-to-maturity to available-for-sale the period	10,069
Tax effect	(3,815)
Net of tax	6,254
Reclassification adjustment for realized gains included in net income	(4,234)	(3,931)	(2,818)
Tax effect	1,682	1,564	986
Net of tax	(2,552)	(2,367)	(1,832)
Amortization of unrealized net losses on held-to-maturity securities transferred from available-for-sale securities	1,986	220	215
Tax effect	(813)	(90)	(91)
Net of tax	1,173	130	124
Unrealized gains (losses) on cash flow hedges	219	(179)	48
Tax effect	(90)	73	(20)
Net of tax	129	(106)	28
Unrealized pension plan gains and (losses):
Unrealized pension plan gains (losses) before reclassifications	(2)	485	(2,119)
Tax effect	1	(198)	866
Net of tax	(1)	287	(1,253)
Reclassification adjustment for realized losses included in net income	407	433	223
Tax effect	(165)	(177)	(91)
Net of tax	242	256	132
Total other comprehensive income (loss)	1,763	(3,595)	1,530
Total comprehensive income	$ 32,845	$ 37,716	$ 20,095