Annual report pursuant to Section 13 and 15(d)

Employee Benefit Plan - Additional Information (Detail)

v3.19.1
Employee Benefit Plan - Additional Information (Detail) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Compensation Related Costs [Abstract]      
Defined contribution plan description We provide a 401(k) defined contribution plan for all regular full-time employees who have completed three months of service.    
Expenses to the plan by employer $ 0.1 $ 0.1 $ 0.1