Consolidated Statements of Comprehensive Income - Unaudited - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 19,430	$ 11,556	$ 37,129	$ 25,508
Unrealized gains (losses) on securities:
Unrealized holding gains (losses) on securities arising during the period	8,059	(5,423)	14,926	(4,964)
Income tax effect	(3,022)	2,034	(5,597)	1,818
Less: reclassification adjustment for (gains) losses on securities included in net income	0	69	(26)	69
Income tax effect	0	(26)	10	(26)
Net unrealized gains (losses)	5,037	(3,346)	9,313	(3,103)
Unrealized gains (losses) on cash flow hedges:
Unrealized gains (losses) on cash flow hedges arising during the period	(813)	446	(3,413)	(1,500)
Income tax effect	305	(167)	1,280	611
Less: reclassification adjustment for (gains) losses included in net income	603	0	603	0
Income tax effect	(226)	0	(226)	0
Net unrealized gains (losses)	(131)	279	(1,756)	(889)
Other comprehensive income (loss), net of tax	4,906	(3,067)	7,557	(3,992)
Comprehensive income	$ 24,336	$ 8,489	$ 44,686	$ 21,516