Quarterly report pursuant to Section 13 or 15(d)

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

v3.19.1
Stockholders' Equity - Summary of Stock Option Activity (Detail) - USD ($)
$ / shares in Units, $ in Thousands
3 Months Ended
Mar. 31, 2019
Mar. 31, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]    
Exercised, Shares (159,355) (309,497)
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 928,675  
Exercised, Shares (159,355)  
Forfeited or expired, Shares (203,876)  
Outstanding, Shares, ending balance 6,842,443  
Vested and expected to vest, Shares 6,842,443  
Exercisable, Shares 2,423,097  
Outstanding, Weighted Average Exercise Price, beginning balance $ 28.15  
Granted, Weighted Average Exercise Price 38.12  
Exercised, Weighted Average Exercise Price 18.18  
Forfeited or expired, Weighted Average Exercise price 27.94  
Outstanding, Weighted Average Exercise Price, ending balance 29.74  
Stock options vested and expected to vest, Weighted Average Exercise Price 29.74  
Exercisable, Weighted Average Exercise Price $ 22.23  
Outstanding, Weighted Average Remaining Contractual Term 5 years 7 months 6 days  
Stock options vested and expected to vest, Weighted Average Remaining Contractual Term 5 years 7 months 6 days  
Exercisable, Weighted Average Remaining Contractual Term 3 years 10 months 24 days  
Aggregate intrinsic value $ 71,329  
Vested and expected to vest, Aggregate Intrinsic Value 71,329  
Exercisable, Aggregate Intrinsic Value $ 42,615