Outstanding Loans and Security Agreements - Schedule of Debt (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2012
Debt Instrument [Line Items]
Unpaid principal balance	$ 658,083	$ 786,495
Current portion of debt	337,583	29,848
Long-term portion of debt	299,229	711,433
Total	636,812	741,281
Unused Borrowing Capacity	$ 1,220	1,220
Interest rate percentage	6.00%
Letter of Credit due December 2021, Non-Recourse
Debt Instrument [Line Items]
Unpaid principal balance	$ 0	0
Current portion of debt	0	0
Long-term portion of debt	0	0
Total	0	0
Recourse debt
Debt Instrument [Line Items]
Unpaid principal balance	416,974	432,623
Current portion of debt	325,428	8,686
Long-term portion of debt	75,962	388,073
Total	401,390	396,759
Senior secured notes \| Senior Secured Notes due March 2025, Non-Recourse
Debt Instrument [Line Items]
Unpaid principal balance		79,698
Current portion of debt		11,994
Long-term portion of debt		66,572
Total		78,566
Senior secured notes \| Senior Secured Notes due March 2030, Non-Recourse
Debt Instrument [Line Items]
Unpaid principal balance	80,988	83,457
Current portion of debt	3,151	2,469
Long-term portion of debt	76,865	79,868
Total	$ 80,016	82,337
Interest rate percentage	6.07%
Term loan \| Term Loan due November 2020, Recourse
Debt Instrument [Line Items]
Unpaid principal balance	$ 1,571	3,286
Current portion of debt	1,536	1,686
Long-term portion of debt	0	1,528
Total	1,536	3,214
Term loan \| Term Loan due September 2028, Non-Recourse
Debt Instrument [Line Items]
Unpaid principal balance	38,337	40,538
Current portion of debt	3,882	2,200
Long-term portion of debt	31,087	34,119
Total	$ 34,969	36,319
Interest rate percentage	7.50%
Term loan \| Senior Secured Notes due October 2020, Non-Recourse
Debt Instrument [Line Items]
Unpaid principal balance		24,723
Current portion of debt		827
Long-term portion of debt		23,089
Total		23,916
Term loan \| Term Loan due December 2021, Non-Recourse
Debt Instrument [Line Items]
Unpaid principal balance	$ 121,784	125,456
Current portion of debt	5,122	3,672
Long-term portion of debt	115,315	119,712
Total	$ 120,437	123,384
Convertible promissory notes \| Convertible Promissory Notes Interest Rate 8% Due December 2019
Debt Instrument [Line Items]
Unpaid principal balance		33,104
Current portion of debt		0
Long-term portion of debt		34,706
Total		34,706
Interest rate percentage	8.00%
Convertible promissory notes \| Convertible Promissory Notes Interest Rate 5% Due December 2020, Recourse
Debt Instrument [Line Items]
Unpaid principal balance	$ 33,104
Current portion of debt	36,482
Long-term portion of debt	0
Total	$ 36,482
Interest rate percentage	5.00%
Convertible promissory notes \| Convertible Promissory Notes Interest Rate 6% Due December 2020, Recourse
Debt Instrument [Line Items]
Unpaid principal balance	$ 289,299	296,233
Current portion of debt	273,410	0
Long-term portion of debt	0	263,284
Total	$ 273,410	263,284
Interest rate percentage	6.00%
Notes \| Notes due July 2024, Recourse
Debt Instrument [Line Items]
Unpaid principal balance	$ 93,000	100,000
Current portion of debt	14,000	7,000
Long-term portion of debt	75,962	88,555
Total	$ 89,962	95,555
Interest rate percentage	10.00%
Non-recourse debt
Debt Instrument [Line Items]
Unpaid principal balance	$ 241,109	353,872
Current portion of debt	12,155	21,162
Long-term portion of debt	223,267	323,360
Total	235,422	344,522
Unused Borrowing Capacity	1,220	1,220
Letters of Credit \| Letter of Credit due December 2021, Non-Recourse
Debt Instrument [Line Items]
Unused Borrowing Capacity	$ 1,220	$ 1,220
Interest rate percentage	2.25%	2.25%
Variable Interest Entity, Primary Beneficiary
Debt Instrument [Line Items]
Current portion of debt	$ 12,155	$ 21,162
Long-term portion of debt	$ 223,267	$ 323,360
PPA IIIa \| Term loan \| Term Loan due September 2028, Non-Recourse
Debt Instrument [Line Items]
Interest rate percentage			7.50%
LIBOR \| Term loan \| Term Loan due November 2020, Recourse
Debt Instrument [Line Items]
Interest rate percentage	4.00%
LIBOR \| Term loan \| Senior Secured Notes due October 2020, Non-Recourse
Debt Instrument [Line Items]
Interest rate percentage	5.25%
LIBOR \| Term loan \| Term Loan due December 2021, Non-Recourse
Debt Instrument [Line Items]
Interest rate percentage	2.50%

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

No definition available.

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- Definition

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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No definition available.

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Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt, classified as current. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount after unamortized (discount) premium and debt issuance costs of long-term debt classified as noncurrent and excluding amounts to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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