Fair Value - Estimated Fair Values and Carrying Values for Customer Receivables and Debt Instruments (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020	Aug. 31, 2020	May 01, 2020
Term loan | Net Carrying Value | Term Loan due September 2028, Non-Recourse
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument	$ 30,869	$ 31,746
Term loan | Net Carrying Value | Term Loan due December 2021, Non-Recourse
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument	111,410	114,138
Term loan | Fair Value | Term Loan due September 2028, Non-Recourse
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument	37,044	37,658
Term loan | Fair Value | Term Loan due December 2021, Non-Recourse
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument	113,165	116,113
Notes | Net Carrying Value | 10.25% Senior Secured Notes due March 2027
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument	68,703	68,614
Notes | Fair Value | 10.25% Senior Secured Notes due March 2027
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument	70,873	71,831
Senior secured notes | Net Carrying Value | 2.5% Green Convertible Senior Notes due August 2025
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument	221,387	99,394
Senior secured notes | Net Carrying Value | Senior Secured Notes due March 2030, Non-Recourse
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument	76,130	77,007
Senior secured notes | Fair Value | 2.5% Green Convertible Senior Notes due August 2025
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument	400,009	426,229
Senior secured notes | Fair Value | Senior Secured Notes due March 2030, Non-Recourse
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument		89,654
Customer financing receivables | Net Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Customer financing receivables	49,395	50,746
Customer financing receivables | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Customer financing receivables	$ 41,039	$ 42,679
10.25% Senior Secured Notes due March 2027
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate percentage				10.25%
10.25% Senior Secured Notes due March 2027 | Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate percentage	10.25%	10.25%
2.5% Green Convertible Senior Notes due August 2025 | Senior secured notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate percentage		2.50%	2.50%
Term Loan due September 2028, Non-Recourse | Term loan
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate percentage	7.50%	7.50%
Senior Secured Notes due March 2030, Non-Recourse | Senior secured notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate percentage	6.07%	6.07%
Senior Secured Notes due March 2030, Non-Recourse | Senior secured notes | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument	$ 85,830
Term Loan due December 2021, Non-Recourse | Term loan
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate percentage	2.50%	2.50%