Other Comprehensive Income Other Comprehensive Income (Loss) (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
Before-tax amount [Abstract]
Foreign currency translation adjustment	$ 21,992	$ 25,085	$ 1,343	$ 940
Net unrealized gain (loss) on derivative instruments designated as cash flow hedges	(1,021)	(1,332)	223	(2,697)
Net hedging loss (gain) reclassified into net income	274	0	274	0
Pension plan benefits liability adjustment	266	(4)	(17)	34
Total other comprehensive income (loss), before tax	21,511	23,749	1,823	(1,723)
Tax (provision) benefit [Abstract]
Foreign currency translation adjustment	(73)	(558)	(3,544)	(243)
Net unrealized gain (loss) on derivative instruments designated as cash flow hedges	343	504	(129)	1,020
Net hedging loss (gain) reclassified into net income	(104)	0	(104)	0
Pension plan benefits liability adjustment	(81)	(1)	5	6
Total other comprehensive income (loss) tax (provision) benefit	85	(55)	(3,772)	783
Net-of-tax amount [Abstract]
Foreign currency translation adjustment	21,919	24,527	(2,201)	697
Net unrealized gain (loss) on derivative instruments designated as cash flow hedges	(678)	(828)	94	(1,677)
Net hedging loss (gain) reclassified into net income	170	0	170	0
Pension plan benefits liability adjustment	185	(5)	(12)	40
Total other comprehensive income (loss), net of tax	$ 21,596	$ 23,694	$ (1,949)	$ (940)