Balance Sheet Components - Accrued Expenses and Other Current Liabilities (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Balance Sheet Related Disclosures [Abstract]
Salaries and related expenses	$ 7,581	$ 2,436
Accrued interest on Notes	2,138	2,138
Other	3,287	2,653
Total accrued expenses and other current liabilities	13,006	$ 7,227
Chief Executive Officer [Member]
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Severance costs	$ 1,500