Accrued Expenses - Summary of Accrued Expenses (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Accrued Liabilities Current [Abstract]
Accrued compensation and benefits	$ 6,132	$ 10,080
Accrued sales and marketing	4,885	3,402
Accrued legal contingency	3,391
Accrued manufacturing	1,149	1,351
Accrued rent obligations	1,112	1,103
Other	3,357	2,882
Total accrued expenses	$ 20,026	$ 18,818