Accrued Payroll Costs (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Payables and Accruals [Abstract]
Payroll and benefits	$ 37,985	$ 37,788
Health insurance liabilities	3,238	2,596
Payroll taxes	2,190	5,270
Workers’ compensation liabilities	1,232	1,232
Total Accrued payroll costs	$ 44,645	$ 46,886