Summary of Significant Accounting Policies - Schedule of Deferred Revenue (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Entity Wide Revenue Major Customer [Line Items]
Deferred revenue	$ 618,792	$ 512,124
Customer Payments
Entity Wide Revenue Major Customer [Line Items]
Deferred revenue	370,754	311,193
Rebates and Incentives
Entity Wide Revenue Major Customer [Line Items]
Deferred revenue	102,827	101,318
SRECs
Entity Wide Revenue Major Customer [Line Items]
Deferred revenue	18,358	13,846
ITCs
Entity Wide Revenue Major Customer [Line Items]
Deferred revenue	$ 126,853	$ 85,767