Accrued Liabilities and Other Long Term Liabilities (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Components of Accrued Liabilities
Accrued commissions	$ 1,332	$ 2,598
Accrued bonuses	1,863	2,562
Accrued vacation	2,316	1,741
Accrued payroll related liabilities	1,152	1,222
Accrued pre-acquisition sales tax liability	1,500	950
Accrued software expense	1,881	312
Other accrued expenses	4,877	4,549
Total	$ 14,921	$ 13,934