Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Net income	$ 21,742	$ 20,040	$ 16,891
Other comprehensive income (loss), net of tax	(684)	3,792	(5,464)
Comprehensive income	21,058	23,832	11,427
Unrealized Gains Losses on Derivatives [Member]
Unrealized gains (losses) on derivatives arising during period	(1,144)	(3,759)	4,159
Less: reclassification adjustment for net loss on derivatives realized in net income	89	83	0
Less: reclassification adjustment for amortization of derivative termination costs	71	0	0
Income tax (expense) benefit	374	1,396	(1,580)
Other comprehensive income (loss) on derivatives, net of tax	(610)	(2,280)	2,579
Noncredit-related Unrealized Gains Losses on Securities with OTTI [Member]
Unrealized holding gains (losses) arising during the period	0	1,828	516
Less: reclassification adjustment for net (gains) losses realized in net income	0	493	0
Income tax (expense) benefit	0	(882)	(196)
Other comprehensive income on available for sale securities, net of tax	0	1,439	320
Unrealized gains losses on securities without OTTI, net of tax [Member]
Unrealized holding gains (losses) arising during the period	(33)	8,201	(13,488)
Less: reclassification adjustment for net (gains) losses realized in net income	(47)	(716)	0
Less: reclassification adjustment for amortization of net unrealized gains on securities transferred from available for sale to held to maturity, realized in interest income	(39)	(13)	0
Income tax (expense) benefit	45	(2,839)	5,125
Other comprehensive income on available for sale securities, net of tax	$ (74)	$ 4,633	$ (8,363)