Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015		Mar. 31, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 13,952		$ 8,136
Unrealized gains (losses) on securities:
Unrealized holding gains on securities arising during the period	459	[1]	9,121	[1]
Income tax effect	(216)	[1]	(3,193)	[1]
Less: reclassification adjustment for gains on securities included in net income	0		(2,832)
Income tax effect	0		992
Net unrealized gains	243		4,088
Unrealized gains (losses) on cash flow hedges:
Unrealized gains (losses) on cash flow hedges arising during the period	(1,946)		664
Income tax effect	778		(232)
Net unrealized gains (losses)	(1,168)		432
Other comprehensive income (loss), net of tax	(925)		4,520
Comprehensive income	$ 13,027		$ 12,656

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