Summary of Significant Accounting Policies - Schedule of Revenues from External Customers (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Entity Wide Revenue Major Customer [Line Items]
Operating leases	$ 23,688	$ 17,302	$ 63,735	$ 46,719
Incentives	7,962	4,310	24,681	16,321
Operating leases and incentives	31,650	21,612	88,416	63,040
Solar energy systems and product sales	50,950	34,464	116,551	75,378
Total revenue	82,600	56,076	204,967	138,418
Solar Energy Systems
Entity Wide Revenue Major Customer [Line Items]
Solar energy systems and product sales	9,890	6,474	22,724	14,567
Products
Entity Wide Revenue Major Customer [Line Items]
Solar energy systems and product sales	$ 41,060	$ 27,990	$ 93,827	$ 60,811