Accumulated Other Comprehensive Income (Schedule of Reclassifications out of Accumulated Other Comprehensive Income) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Provision for income taxes	$ 16,045	$ 18,786	$ 60,693	$ 58,745
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax			103
Reclassifications out of Accumulated Other Comprehensive Income [Member]
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	272	1,163	79	2,027
Provision for income taxes	67	329	(24)	542
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	205	834	103	1,485
Interest Rate Swaps [Member] | Reclassifications out of Accumulated Other Comprehensive Income [Member]
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	(268)	(131)	(795)	(632)
Foreign Currency Exchange Contracts [Member] | Reclassifications out of Accumulated Other Comprehensive Income [Member]
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	$ 540	$ 1,294	$ 874	$ 2,659