Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Net income	$ 37,187	$ 34,822	$ 27,170
Unrealized (losses) gains on securities available-for-sale:
Unrealized (losses) gains arising during the period(net of tax of $(840), $2,383, and $(4,234), respectively)	(1,558)	4,423	(7,863)
Unrealized (losses) gains on hedging instruments:
Unrealized (losses) gains arising during the period (net of tax of $(41), $0, and $8, respectively)	(76)		16
Minimum pension liability adjustment (net of tax of$61, ($69), and $111, respectively)	114	(127)	206
Reclassification adjustment for impairment of equity security realized in income (net of tax of $36, $0, and $0, respectively)	67
Reclassification adjustment for securities losses reclassified out of other comprehensive income into loss on sale of securities available-for-sale (net of tax of $0, $3, and $2, respectively)		6	3
Other comprehensive (loss) income	(1,453)	4,302	(7,638)
Comprehensive income	$ 35,734	$ 39,124	$ 19,532