Accumulated Other Comprehensive Income (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Accumulated Other Comprehensive Income [Roll Forward]
Foreign Currency Translation Adjustment, Beginning Balance	$ 42,394	$ 45,905
Foreign currency translation adjustment	5,616	(3,511)	21,877
Foreign Currency Translation Adjustment, Ending Balance	48,010	42,394	45,905
Defined Benefit Plans, Beginning Balance	(20)	22
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax, Portion Attributable to Parent	293	42	(344)
Defined Benefit Plans, Ending Balance	(313)	(20)	22
Net Unrealized Losses on Cash Flow Hedges, Beginning Balance	(4,479)	(5,813)
Net Unrealized Losses on Cash Flow Hedges, Current Period Change	4,053	1,334	(1,590)
Net Unrealized Losses on Cash Flow Hedges, Ending Balance	(426)	(4,479)	(5,813)
Accumulated Other Comprehensive Income, Beginning Balance	37,895	40,114
Accumulated Other Comprehensive Income, Current Period Change	9,376	(2,219)
Accumulated Other Comprehensive Income, Ending Balance	47,271	37,895	40,114
Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Accumulated Other Comprehensive Income [Roll Forward]
Net Unrealized Losses on Cash Flow Hedges, Current Period Change	$ 4,053	$ 1,334