Quarterly report pursuant to Section 13 or 15(d)

Stockholders' Equity - Summary of RSU Activity (Detail)

v3.10.0.1
Stockholders' Equity - Summary of RSU Activity (Detail) - Unvested RSUs - $ / shares
6 Months Ended
Jun. 30, 2018
Jun. 30, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]    
Shares, Unvested as of December 31, 2017 1,685,000  
Shares, Granted 788,987  
Shares, Forfeited (310,352)  
Shares, Vested (365,933)  
Shares, Unvested as of June 30, 2018 1,797,702  
Shares, Vested and unreleased 3,384  
Shares, Outstanding as of June 30, 2018 1,801,086  
Weighted Average Grant Date Fair Value, Unvested as of December 31, 2017 $ 16.90  
Weighted Average Grant Date Fair Value, Granted 36.69 $ 15.78
Weighted Average Grant Date Fair Value, Forfeited 20.23  
Weighted Average Grant Date Fair Value, Vested 15.11  
Weighted Average Grant Date Fair Value, Unvested as of June 30, 2018 $ 25.38