Deferred Income Tax Assets and Liabilities (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Current deferred tax assets:
Accrued expenses	$ 12,934	$ 12,575
Unrealized loss on foreign currency current	2,026
Other current	8	2,383
Valuaton allowance	(3,492)	(6,054)
Total current deferred tax assets	11,476	8,904
Current deferred tax liabilities:
Deferred tax liability on unremitted earnings of foreign subsidiary	(7,596)	(4,746)
Total current deferred tax liabilities	(7,596)	(4,746)
Non-current deferred tax assets:
Stock compensation expense	8,865	7,630
Long-term accrued expesnes	3,067
Net operating loss and charitable contribution carryovers	23,255	26,219
Property and equipment	8,994	8,641
Future uncertain tax position offset	3,780	13,638
Unrealized loss on foreign currency non-current	921	5,644
Foreign tax credit	5,392	3,177
Other non-current	1,767	190
Valuation allowance	(22,406)	(33,889)
Total non-current deferred tax assets	33,635	31,250
Non-current deferred tax liabilities:
Intangible assets deferred tax assets	(779)	(1,009)
Total non-current gross deferred tax liabilities	$ (779)	$ (1,009)