CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Comprehensive Income [Abstract]
Net income	$ 41,311	$ 18,565	$ 19,925
Unrealized gains and losses on securities available-for-sale:
Unrealized holding (losses) gains on available for sale securities	(2,991)	6,966	(8,741)
Tax effect	1,196	(2,635)	3,578
Net of tax amount	$ (1,795)	$ 4,331	(5,163)
Reclassification adjustments for OTTI losses included in income			652
Tax effect			(178)
Net of tax amount			474
Reclassification adjustment for realized gains arising during this period	$ (3,931)	$ (2,818)	(2,363)
Tax effect	1,564	986	645
Net of tax amount	$ (2,367)	$ (1,832)	(1,718)
Unrealized holding losses on securities transferred from available-for-sale to held-to-maturity securities			(2,612)
Tax effect			1,064
Net of tax amount			(1,548)
Amortization of net unrealized holding losses (gains) on securities transferred from available-for-sale to held-to-maturity securities	$ 220	$ 215	(58)
Tax effect	(90)	(91)	19
Net of tax amount	130	124	$ (39)
Unrealized holding (loss) gain on cash flow hedge	(179)	48
Tax effect	73	(20)
Net of tax amount	(106)	28
Pension plan:
Actuarial gains (losses)	918	(1,896)	$ 654
Tax effect	(375)	775	(267)
Net of tax amount	543	(1,121)	387
Total other comprehensive (loss) income	(3,595)	1,530	(7,607)
Total comprehensive income	$ 37,716	$ 20,095	$ 12,318