Accrued Liabilities Long-term liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Accrued Liabilities [Abstract]
Liabilities for contracts	$ 11,591	$ 14,020
contract settlement	1,250	1,667
Capital Lease Obligations, Noncurrent	30,641	0
Accrued Employee Benefits	990	962
Accrued Rent	1,763	1,779
Contract with Customer, Liability, Noncurrent	346	468
Other Accrued Liabilities, Noncurrent	1,429	1,696
OTHER LONG-TERM LIABILITIES	$ 48,010	$ 20,592	[1]

[1] December 31, 2018 balances were derived from audited consolidated financial statements.