Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 15,289	$ 11,662	$ 40,797	$ 30,036
Unrealized gains (losses) on securities:
Unrealized holding gains (losses) on securities arising during the period	261	(1,886)	(4,703)	11,335
Income tax effect	(98)	660	1,720	(3,967)
Reclassification adjustment for (gains) losses on securities included in net income	16	0	85	(3,191)
Income tax effect	(6)	0	(32)	1,117
Net unrealized gains (losses)	173	(1,226)	(2,930)	5,294
Unrealized gains (losses) on cash flow hedges:
Unrealized gains (losses) on cash flow hedges arising during the period	(2,341)	661	(3,841)	(296)
Income tax effect	877	(235)	1,488	100
Net unrealized gains (losses)	(1,464)	426	(2,353)	(196)
Other comprehensive income (loss), net of tax	(1,291)	(800)	(5,283)	5,098
Comprehensive income	$ 13,998	$ 10,862	$ 35,514	$ 35,134