Other Expense, Net - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Other Non Operating Income Expense [Line Items]
Other expense, net	$ 800
Financing and debt issuance costs	656		$ 47
Interest expense	$ (147)	$ (182)	(50,281)
Change in fair value of debt instruments			50,000
Silicon Valley Bank Credit Facility [Member]
Other Non Operating Income Expense [Line Items]
Interest expense			$ 300