Stock-Based Compensation - Summary of Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Compensation expense recognized	$ 4,006	$ 1,727	$ 10,427	$ 6,037
Cost of Operating Leases and Incentives
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Compensation expense recognized	545	61	842	173
Cost of Solar Energy Systems and Product Sales
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Compensation expense recognized	61	74	173	141
Sales and Marketing
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Compensation expense recognized	1,656	297	3,292	793
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Compensation expense recognized	1	75	127	214
General and Administration
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Compensation expense recognized	$ 1,743	$ 1,220	$ 5,993	$ 4,716