Annual report pursuant to Section 13 and 15(d)

Employee Benefit Plan (Details)

v3.8.0.1
Employee Benefit Plan (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Postemployment Benefits [Abstract]      
Company's matching contribution percent 25.00%    
Percent of participant's compensation 6.00%    
Matching contribution costs to the Plan $ 0.7 $ 1.1 $ 4.0
Vesting percentage for employees hired prior to July 2017 100.00%    
Vesting period for employees hired after July 2017 3 years