Accrued Expenses (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Schedule of Accrued Liabilities [Line Items]
Payroll and other employee related costs	$ 6,458	$ 6,435
Professional services and consulting and other vendor fees	6,927	4,686
Sales commissions	294	446
Other	381	452
Total	$ 14,060	$ 12,019