Summary of Significant Accounting Policies - Schedule of Revenues from External Customers (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Revenue, Major Customer [Line Items]
Total Revenue	$ 194,504	$ 144,363
Customer agreements and incentives
Revenue, Major Customer [Line Items]
Customer agreements and incentives	99,850	66,990
Customer agreements
Revenue, Major Customer [Line Items]
Customer agreements and incentives	78,528	61,649
Incentives
Revenue, Major Customer [Line Items]
Customer agreements and incentives	21,322	5,341
Solar energy systems and product sales
Revenue, Major Customer [Line Items]
Total Revenue	94,654	77,373
Solar energy systems
Revenue, Major Customer [Line Items]
Total Revenue	58,436	33,998
Products
Revenue, Major Customer [Line Items]
Total Revenue	$ 36,218	$ 43,375