Quarterly report pursuant to Section 13 or 15(d)

Stockholders' Equity - Summary of Stock Option Activity (Detail)

v3.19.3
Stockholders' Equity - Summary of Stock Option Activity (Detail) - USD ($)
$ / shares in Units, $ in Thousands
9 Months Ended
Sep. 30, 2019
Sep. 30, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]    
Exercised, Shares (192,716) (781,191)
2014 EIP and Inducement Plan    
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]    
Outstanding, Shares, beginning balance 6,276,999  
Granted, Shares 2,100,225  
Exercised, Shares (192,716)  
Forfeited or expired, Shares (819,920)  
Outstanding, Shares, ending balance 7,364,588  
Vested and expected to vest, Shares 7,364,588  
Exercisable, Shares 3,284,621  
Outstanding, Weighted Average Exercise Price, beginning balance $ 28.15  
Granted, Weighted Average Exercise Price 29.86  
Exercised, Weighted Average Exercise Price 17.92  
Forfeited or expired, Weighted Average Exercise price 31.74  
Outstanding, Weighted Average Exercise Price, ending balance 28.51  
Stock options vested and expected to vest, Weighted Average Exercise Price 28.51  
Exercisable, Weighted Average Exercise Price $ 25.52  
Outstanding, Weighted Average Remaining Contractual Term 5 years 6 months  
Stock options vested and expected to vest, Weighted Average Remaining Contractual Term 5 years 6 months  
Exercisable, Weighted Average Remaining Contractual Term 3 years 6 months  
Aggregate intrinsic value $ 968  
Vested and expected to vest, Aggregate Intrinsic Value 968  
Exercisable, Aggregate Intrinsic Value $ 820