Accumulated Other Comprehensive Income (Schedule of Reclassifications out of Accumulated Other Comprehensive Income) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Provision for income taxes	$ 64,604	$ 75,467	$ 82,330
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	2,002	1,890
Reclassifications out of Accumulated Other Comprehensive Income [Member]
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	2,758	2,569	5,248
Provision for income taxes	756	679	1,623
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	2,002	1,890	3,625
Interest Rate Swaps [Member] | Reclassifications out of Accumulated Other Comprehensive Income [Member]
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	(1,064)	(900)	(690)
Foreign Currency Exchange Contracts [Member] | Reclassifications out of Accumulated Other Comprehensive Income [Member]
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	$ 3,822	$ 3,469	$ 5,938