XML 44 R33.htm IDEA: XBRL DOCUMENT v3.7.0.1
Stock-Based Compensation Expense - Additional Information (Detail) - USD ($)
6 Months Ended
Mar. 15, 2017
Jun. 30, 2017
Mar. 16, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Vesting period   4 years  
Number of common stock repurchased   9,534  
Purchase price of common stock by employees (as a percent)   85.00%  
Employee Stock Purchase Plan [Member] | Maximum [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Employee withholding percentage   15.00%  
Restricted Stock And Restricted Stock Units [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Unrecognized compensation expense   $ 30,577,992  
Unrecognized compensation expense, recognition period   2 years 11 months 16 days  
Options to Purchase Common Stock [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Unrecognized compensation expense, recognition period   2 years 10 months 24 days  
Unrecognized compensation cost, stock options   $ 14,100,000  
Stock options vested, fair value   $ 3,200,000  
Stock options granted, weighted-average grant date fair value   $ 6.65  
Employee Stock [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Common stock issued to employees (in shares) 138,085    
Aggregate proceeds from issuance of common stock to employees $ 1,500,000    
Share issued, price per share (in dollars per share) $ 12.79   $ 10.60
Closing price of shares issued (in dollars per share) $ 15.05   $ 12.47