Condensed Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Statement of Comprehensive Income [Abstract]
Net income	$ 47,532	$ 76,730	$ 156,495	$ 200,879
Other comprehensive (loss) income:
Change in foreign currency translation adjustment	(12,890)	6,928	(15,617)	4,099
Available for sale securities:
Change in net unrealized gains	(911)	1,623	(182)	(1,470)
Less: reclassification adjustment for net (gains) losses included in net income	(96)	44	(961)	13
Net change (net of tax effect)	(1,007)	1,667	(1,143)	(1,457)
Loss on pension liability	(45)	0	(45)	(334)
Cash flow hedges:
Change in unrealized gains	(6,809)	3,896	(4,197)	(1,399)
Less: reclassification adjustment for net (gains) losses included in net income	(1,500)	1,262	(4,448)	3,574
Net change (net of tax effect)	(8,309)	5,158	(8,645)	2,175
Other comprehensive (loss) income	(22,251)	13,753	(25,450)	4,483
Comprehensive income	$ 25,281	$ 90,483	$ 131,045	$ 205,362