Annual report pursuant to Section 13 and 15(d)

Summary of Significant Accounting Policies - Schedule of Deferred Revenue (Details)

v3.8.0.1
Summary of Significant Accounting Policies - Schedule of Deferred Revenue (Details) - USD ($)
$ in Thousands
Dec. 31, 2017
Dec. 31, 2016
Revenue, Major Customer [Line Items]    
Deferred revenue $ 661,737 $ 654,250
Customer payments    
Revenue, Major Customer [Line Items]    
Deferred revenue 436,859 400,233
Rebates and incentives    
Revenue, Major Customer [Line Items]    
Deferred revenue 108,823 110,576
SRECs    
Revenue, Major Customer [Line Items]    
Deferred revenue 30,453 22,437
ITCs    
Revenue, Major Customer [Line Items]    
Deferred revenue $ 85,602 $ 121,004