Summary of Significant Accounting Policies - Schedule of Revenues from External Customers (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Revenue, Major Customer [Line Items]
Operating leases	$ 47,600	$ 34,144	$ 129,696	$ 92,451
Incentives	10,862	9,006	42,201	30,633
Operating leases and incentives	58,462	43,150	171,897	123,084
Solar energy systems and product sales	82,829	68,883	211,359	210,230
Total revenue	141,291	112,033	383,256	333,314
Solar energy systems
Revenue, Major Customer [Line Items]
Solar energy systems and product sales	30,734	27,585	79,431	93,655
Products
Revenue, Major Customer [Line Items]
Solar energy systems and product sales	$ 52,095	$ 41,298	$ 131,928	$ 116,575