Acquisitions - Additional Information (Details) - USD ($) $ in Thousands		1 Months Ended			7 Months Ended	12 Months Ended
	Apr. 01, 2017	Apr. 30, 2016	Oct. 31, 2015	Apr. 30, 2015	Oct. 31, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
Business acquisition, net of cash acquired						$ 5,000	$ 19,575	$ 36,384
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 acquired business to total revenue							$ 16,900
Clean Energy Experts, LLC | Scenario Forecast
Business Acquisition [Line Items]
Business acquisition contingent cash payment	$ 9,100
Business acquisition contingent share issuance	600,000
Business acquisition of compensation expenses	2 years