Accrued Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Payables and Accruals [Abstract]
Payroll and related liabilities	$ 3,247	$ 3,659
Other	4,599	7,105
Total accrued liabilities	$ 7,846	$ 10,764	[1]

[1] See Note 2.