v3.10.0.1
Stockholders' Equity (Details) - USD ($)
$ / shares in Units, $ in Thousands
 6 Months Ended
May 22, 2018
Jan. 01, 2018
Jan. 01, 2017
Jun. 30, 2018
Dec. 31, 2017
Stockholders' Equity          
Proceeds from issuance of common stock, net of offering costs       $ 330,862  
Authorized shares of capital stock       205,000,000  
Authorized shares of common stock       200,000,000 200,000,000
Authorized shares of preferred stock       5,000,000 5,000,000
Shares of common stock reserved for future issuance          
Outstanding stock options       4,659,638  
Possible future issuance under 2014 Equity Incentive Plan       6,096,824  
Outstanding restricted stock units       1,280,627  
Available for future issuance under employee stock purchase plan       1,000,000  
Total shares of common stock reserved for future issuance       13,037,089  
Stock options          
Stockholders equity compensation          
Granted (in shares)       655,524  
Weighted-average exercise price (in dollars per share)       $ 84.12  
Equity Incentive Plan 2014 | Stock options          
Stockholders equity compensation          
Granted (in shares)   2,625,292      
Weighted-average exercise price (in dollars per share)     $ 2,357,579.00    
Common Stock          
Stockholders' Equity          
Shares issued 3,833,334     3,833,334  
Proceeds from issuance of common stock, net of offering costs $ 330,800        
Common Stock | Underwriters' over-allotment option          
Stockholders' Equity          
Shares issued 500,000