Accrued Liabilities (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Schedule of Accrued Liabilities [Line Items]
Accrued payroll and benefits	$ 38,270	$ 39,621
Accrued sales rebate	9,383	8,333
Accrued sales tax and value added tax	5,341	5,253
Accrued warranty	3,806	4,050
Accrued sales and marketing expenses	3,868	4,088
Accrued accounts payable	3,915	2,866
Accrued professional fees	1,485	2,349
Accrued income taxes	1,317	572
Other	6,329	7,115
Total	$ 73,714	$ 74,247