Accrued Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Accrued Liabilities, Current [Abstract]
Accrued salaries, wages and benefits	$ 7,676	$ 9,632
Accrual for insurance liabilities	5,259	5,233
Property taxes	640	513
Sales taxes	1,813	1,836
Interest	23	46
Other accrued expenses	231	613
Total accrued liabilities	$ 15,642	$ 17,873