Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Statement of Comprehensive Income [Abstract]
Net income		$ 11,556	$ 10,233	$ 25,508	$ 18,374
Unrealized gains (losses) on securities:
Unrealized holding gains (losses) on securities arising during the period	[1]	(5,423)	4,101	(4,964)	13,222
Income tax effect	[1]	2,034	(1,435)	1,818	(4,628)
Reclassification adjustment for (gains) losses on securities included in net income		69	(359)	69	(3,191)
Income tax effect		(26)	125	(26)	1,117
Net unrealized gains (losses)		(3,346)	2,432	(3,103)	6,520
Unrealized gains (losses) on cash flow hedges:
Unrealized gains (losses) on cash flow hedges arising during the period		446	(1,621)	(1,500)	(957)
Income tax effect		(167)	567	611	335
Net unrealized gains (losses)		279	(1,054)	(889)	(622)
Other comprehensive income (loss), net of tax		(3,067)	1,378	(3,992)	5,898
Comprehensive income		$ 8,489	$ 11,611	$ 21,516	$ 24,272

[1] Includes immaterial gains or losses on foreign currency items.