Revenue Recognition - Schedule of Significant Changes in Contract Assets and Liabilities (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Contractors [Abstract]
Contract assets	$ 0	$ 680
Change in Contract Asset	$ (680)
Percent Change in Contract Asset	(100.00%)
Contract liabilities	$ (446)	(5)
Change in Contract Liability	$ (441)
Percent Change in Contract Liability	8820.00%
Net contract assets (liabilities)	$ (446)	$ 675
Change in Net Contract Assets (Liabilities)	$ (1,121)
Percent Change in Net Contract Assets (Liabilities)	(166.10%)