Stockholders' Equity - Summary of Option Activity (Detail) - 6 months ended Jun. 30, 2015 - $ / shares	Total
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Number of Shares, Outstanding at beginning of period	3,196,100
Number of Shares, Granted	271,614
Number of Shares, Exercised	(75,050)
Number of Shares, Forfeitures	(114,237)
Number of Shares, Outstanding at end of period	3,278,427
Weighted Average Exercise Price Per Share, Outstanding at beginning of period	$ 4.32
Weighted Average Exercise Price Per Share, Granted	10.23
Weighted average Exercise Price Per Share, Exercised	4.04
Weighted Average Exercise Price Per Share, Forfeitures	12.57
Weighted Average Exercise Price Per Share, Outstanding at end of period	$ 5.44