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, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax			$ 1,485
Provision for income taxes	18,786	19,639	58,745	62,606
Reclassifications out of Accumulated Other Comprehensive Income [Member]
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	1,163	1,267	2,027	4,628
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	834	872	1,485	3,194
Provision for income taxes	329	395	542	1,434
Interest Rate Swaps [Member] | Reclassifications out of Accumulated Other Comprehensive Income [Member]
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	(131)	(112)	(632)	(574)
Foreign Currency Exchange Contracts [Member] | Reclassifications out of Accumulated Other Comprehensive Income [Member]
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	$ 1,294	$ 1,379	$ 2,659	$ 5,202