Accounts Payable and Accrued Expenses - Summary of Earnout Liabilities (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Business Acquisition Contingent Consideration [Line Items]
Fair value adjustment	$ (330)	$ (5,689)
Less: current portion of earnout			$ (2,989)
Energy Solutions Segment [Member]
Business Acquisition Contingent Consideration [Line Items]
Earnout liability at beginning of period	4,475	24,214
Fair value adjustment	(330)	(5,689)
Compensation expense adjustment	222	918
Payment	(2,862)	(15,193)
Other reclassification	(1,440)
Foreign currency translation adjustment	$ (65)	729
Total earnout liability at end of period		4,979
Less: current portion of earnout		(3,514)
Balance of long term portion of earnout recorded in other liabilities at end of period		$ 1,465