Accrued Liabilities (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Accrued Liabilities [Abstract]
Accrued salaries and benefits	$ 8,444	$ 7,642
Accrued Bonuses, Current	4,210	3,627
Accrued value added tax	1,064	1,114
Other Accrued Liabilities, Current	4,092	3,676
Accrued liabilities	$ 17,810	$ 16,059