Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Compensation - Stock Options - Additional Information (Detail)

v3.7.0.1
Stock-Based Compensation - Stock Options - Additional Information (Detail) - USD ($)
$ in Millions
1 Months Ended 6 Months Ended
Jul. 31, 2017
Jun. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Total unrecognized stock-based compensation expense related to non-vested stock options   $ 9.2
Unrecognized stock-based compensation expense related to non-vested stock options period of recognition   3 years 1 month 6 days
Dividend yield percentage   0.00%
IPO [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Number of stock options vested and expected to vest   1,159,266
Scenario, Forecast [Member] | IPO [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Compensation expense $ 5.6  
Minimum [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Stock option, vesting period   2 years
Maximum [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Stock option, vesting period   6 years
Acceleration Vesting [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Percentage of vesting   25.00%