Fair Value - Estimated Fair Values and Carrying Values for Customer Receivables and Debt Instruments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Jan. 18, 2018	Dec. 31, 2014
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate percentage	6.00%
Notes | Net Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument	$ 89,962	$ 95,555
Notes | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument	97,512	99,260
Customer financing receivables | Net Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Customer financing receivables	55,855	72,676
Customer financing receivables | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Customer financing receivables	44,002	51,541
Term Loan due November 2020, Recourse | Term loan | Net Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument	1,536	3,214
Term Loan due November 2020, Recourse | Term loan | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument	$ 1,590	3,311
Term Loan due November 2020, Recourse | LIBOR | Term loan
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
LIBOR margin (as a percentage)	4.00%
Term Loan due November 2020, Recourse | LIBOR | Affiliated entity
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
LIBOR margin (as a percentage)	4.00%
Convertible Promissory Notes due December 2019 and 2020, Recourse | Convertible promissory notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate percentage	5.00%
Convertible Promissory Notes due December 2019 and 2020, Recourse | Convertible promissory notes | Net Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument	$ 36,482	34,706
Convertible Promissory Notes due December 2019 and 2020, Recourse | Convertible promissory notes | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument	$ 32,070	31,546
Convertible Promissory Notes due December 2019 and 2020, Recourse | Affiliated entity | Convertible promissory notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate percentage	8.00%		8.00%	8.00%
Convertible Promissory Notes One due December 2020 | Convertible promissory notes | Net Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument	$ 273,410	263,284
Convertible Promissory Notes One due December 2020 | Convertible promissory notes | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument	$ 302,047	353,368
Notes due July 2024, Recourse | Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate percentage	10.00%
Senior Secured Notes due March 2025, Non-Recourse | Senior secured notes | Net Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument	$ 0	78,566
Senior Secured Notes due March 2025, Non-Recourse | Senior secured notes | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument	$ 0	80,838
Term Loan due September 2028, Non-Recourse | Term loan
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate percentage	7.50%
Term Loan due September 2028, Non-Recourse | Term loan | Net Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument	$ 34,969	36,319
Term Loan due September 2028, Non-Recourse | Term loan | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument	41,108	39,892
Term Loan due October 2020, Non-Recourse | Term loan | Net Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument	0	23,916
Term Loan due October 2020, Non-Recourse | Term loan | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument	$ 0	25,441
Term Loan due October 2020, Non-Recourse | LIBOR | Term loan
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
LIBOR margin (as a percentage)	5.25%
Term Loan due October 2020, Non-Recourse | LIBOR | Affiliated entity
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
LIBOR margin (as a percentage)	5.25%
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%
Senior Secured Notes due March 2030, Non-Recourse | Senior secured notes | Net Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument	$ 80,016	82,337
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	87,618	85,917
Term Loan due December 2021, Non-Recourse | Term loan | Net Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument	120,436	123,384
Term Loan due December 2021, Non-Recourse | Term loan | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument	$ 120,510	$ 123,040
Term Loan due December 2021, Non-Recourse | LIBOR | Term loan
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
LIBOR margin (as a percentage)	2.50%
Term Loan due December 2021, Non-Recourse | LIBOR | Affiliated entity
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
LIBOR margin (as a percentage)	2.50%