Annual report pursuant to Section 13 and 15(d)

Acquisitions - Additional Information (Details)

v3.8.0.1
Acquisitions - Additional Information (Details) - USD ($)
$ in Thousands
1 Months Ended 7 Months Ended 12 Months Ended
Apr. 30, 2016
Oct. 31, 2015
Apr. 30, 2015
Oct. 31, 2016
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Apr. 01, 2017
Business Acquisition [Line Items]                
Business acquisition, net of cash acquired         $ 0 $ 5,000 $ 19,575  
Clean Energy Experts, LLC                
Business Acquisition [Line Items]                
Cash payment     $ 25,000          
Business acquisition shares of common stock     1,900,000          
Purchase consideration amount on issuance of shares     $ 19,100          
Business acquisition payment of cash     $ 15,000          
Business acquisition, shares issued 250,000 250,000 1,400,000 500,000        
Business acquisition, net of cash acquired $ 5,000 $ 5,000   $ 10,000        
Business acquisition contingent cash payment               $ 8,800
Business acquisition contingent share issuance               599,999
Business acquisition acquired business to total revenue             $ 16,900