Other Comprehensive Income Other Comprehensive Income (Loss) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Before-tax amount [Abstract]
Foreign currency translation adjustment	$ 6,798	$ (52,847)	$ (20,649)	$ (24,145)
Net unrealized gain (loss) on derivative instruments designated as cash flow hedges	1,336	(1,365)	1,244	(1,365)
Pension plan benefits liability adjustment	263	19	(283)	38
Total other comprehensive income (loss), before tax	8,397	(54,193)	(19,688)	(25,472)
Tax (provision) benefit [Abstract]
Foreign currency translation adjustment	377	476	(3,471)	315
Net unrealized gain (loss) on derivative instruments designated as cash flow hedges	(491)	516	(472)	516
Pension plan benefits liability adjustment	(80)	3	86	7
Total other comprehensive income (loss) tax (provision) benefit	(194)	995	(3,857)	838
Net-of-tax amount [Abstract]
Foreign currency translation adjustment	7,175	(52,371)	(24,120)	(23,830)
Net unrealized gain (loss) on derivative instruments designated as cash flow hedges	845	(849)	772	(849)
Pension plan benefits liability adjustment	183	22	(197)	45
Total other comprehensive income (loss), net of tax	$ 8,203	$ (53,198)	$ (23,545)	$ (24,634)