Summary of Significant Accounting Policies - Schedule of Deferred Revenue (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Entity Wide Revenue Major Customer [Line Items]
Deferred revenue	$ 654,250	$ 618,792
Customer Payments
Entity Wide Revenue Major Customer [Line Items]
Deferred revenue	400,233	370,754
Rebates and Incentives
Entity Wide Revenue Major Customer [Line Items]
Deferred revenue	110,576	102,827
SRECs
Entity Wide Revenue Major Customer [Line Items]
Deferred revenue	22,437	18,358
ITCs
Entity Wide Revenue Major Customer [Line Items]
Deferred revenue	$ 121,004	$ 126,853