Annual report pursuant to Section 13 and 15(d)

Employee Benefit Plan - Additional Information (Details)

v3.8.0.1
Employee Benefit Plan - Additional Information (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2017
Mar. 01, 2017
Dec. 31, 2016
Dec. 31, 2015
Compensation And Retirement Disclosure [Abstract]        
Percentage of matching contribution of each participants   100.00% 100.00% 100.00%
Maximum contribution percentage of participating employees   6.00% 6.00% 6.00%
Year of service on which employer's matching contribution under 401K plan will be 100% vested 5 years      
Defined Contribution Plan, Employers Matching Contribution, Annual Vesting Percentage 20.00%      
Company's contribution to 401K plan $ 1.4   $ 0.4 $ 2.3