Income Taxes - Income Tax Provision (Benefit) Differs from Computed Using Federal Statutory Rate Applied to Income before Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Tax provision computed at the federal statutory rate	$ (17,619)	$ (15,236)	$ (12,822)
State tax, net of federal benefit	232	66	(246)
Research credits	(2,974)	(2,134)	(2,254)
FIN 48 uncertain tax positions	0	0	0
Change in tax credit carryforwards	(4,965)	0	0
Transaction costs	0	(11)	880
Officers compensation	1,577	1,895	2,178
Stock based compensation	535	299	501
Permanent items and other	(487)	21,742	(1,080)
Domestic manufacturing deduction	0	(630)	767
Tax differential on foreign earnings	1,435	1,570	1,123
Change in tax rate	(903)	(519)	(283)
Valuation allowance	23,575	(4,856)	36,734
Total income tax provision	$ 406	$ 2,186	$ 25,498