XML 78 R60.htm IDEA: XBRL DOCUMENT v3.8.0.1
Employee Benefit Plan (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Retirement Benefits [Abstract]      
Employer matching contribution for employee's contributions of the first 3% of eligible compensation 100.00%    
Percentage of eligible compensation, matched 100% by employer 3.00%    
Employer matching contribution for employee's contributions of the next 2% of eligible compensation 50.00%    
Percentage of eligible compensation, matched 50% by employer 2.00%    
Company's matching contributions to the plan $ 0.4 $ 0.4 $ 0.3