Consolidated Statements Of Comprehensive Income (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Statement of Comprehensive Income [Abstract]
Net income	$ 34,500	$ 32,052
Unrealized gains (losses) on securities
Before tax	22,526	(7,455)
Tax effect	(8,804)	2,806
Net of tax	13,722	(4,649)
Less: Reclassification of net (losses) gains included in net income
Before tax	(33)	251
Tax effect	13	(100)
Net of tax	(20)	151
Net unrealized gains (losses) on securities	13,742	(4,800)
Unrealized (losses) gains on derivative instruments
Before tax	(98)	1,474
Tax effect	39	(586)
Net unrealized (losses) gains on derivative instruments	(59)	888
Foreign currency translation adjustment
Before tax	(9,959)	(6,304)
Tax effect	2,559	1,438
Net foreign currency translation adjustment	(7,400)	(4,866)
Total other comprehensive income (loss)	6,283	(8,778)
Comprehensive income	$ 40,783	$ 23,274