Accrued Expenses (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Components of accrued expenses
Accrued commissions	$ 2,229	$ 2,598
Accrued bonuses	2,245	2,562
Accrued vacation	1,838	1,741
Accrued software expense	1,668	393
Accrued sales and use tax	1,482	1,026
Accrued payroll related liabilities	1,364	1,222
Income tax related accruals	498	605
Short-term portion of lease abandonment accrual	580	580
Deferred rent	526	439
Other accrued expenses	1,850	2,768
Total	$ 14,280	$ 13,934