Revenue Recognition - Schedule of Significant Changes in Contract Assets and Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Contractors [Abstract]
Contract assets	$ 258	$ 680
Change in Contract Asset	$ (422)
Percent Change in Contract Asset	(62.10%)
Contract liabilities	$ (4)	(5)
Change in Contract Liability	$ 1
Percent Change in Contract Liability	(20.00%)
Net contract assets (liabilities)	$ 254	$ 675
Change in Net Contract Assets (Liabilities)	$ (421)
Percent Change in Net Contract Assets (Liabilities)	(62.40%)