Acquisitions (Details 2) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2018
Carbon California [Member]
Business Acquisition [Line Items]
Revenue	$ 8,180	$ 20,283
Net (loss) income before non-controlling interests	(3,013)	4,256
Net loss attributable to non-controlling interests	(3,619)	(2,504)
Net income attributable to controlling interests before preferred shares	$ 607	$ 7,739
Net income per share, basic	$ 0.27	$ 1.01
Net income per share, diluted	$ 0.09	$ 0.84
OIE Membership Acquisition [Member]
Business Acquisition [Line Items]
Revenue	$ 23,682	$ 54,841
Net (loss) income before non-controlling interests	(2,758)	3,046
Net loss attributable to non-controlling interests	(3,619)	(2,505)
Net income attributable to controlling interests before preferred shares	$ 1,687	$ 5,551
Net income per share, basic	$ 0.11	$ 0.76
Net income per share, diluted	$ 0.04	$ 0.54