Income Taxes - Schedule of Reconciliation of Statutory Federal Income Tax Rate (Detail)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Effective Income Tax Rate Continuing Operations Tax Rate Reconciliation [Abstract]
Federal tax provision at statutory rate	35.00%	35.00%	35.00%
State taxes (net of Federal benefit)	0.60%	0.40%	1.40%
Stock-based compensation	0.10%	0.10%	(0.20%)
Non-deductible officer compensation	0.20%	0.10%	(1.80%)
Change in valuation allowance		(40.50%)	(52.10%)
Research and development credits	(0.20%)	(1.50%)	17.10%
Other	0.10%	0.20%	0.30%
Effective income tax rate	35.80%	(6.20%)	(0.30%)