Accrued Expenses (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Payables and Accruals [Abstract]
Payroll taxes	$ 1,893	$ 1,786
Payroll	3,141	2,075
Bonuses	5,778	2,736
Commissions	894	912
Vacation	5,066	4,362
Royalties	1,368	1,310
Value-added tax	1,158	1,018
Other accrued expenses	7,971	5,998
Total	$ 27,269	$ 20,197