Debt - Narrative (Details)						3 Months Ended		7 Months Ended	9 Months Ended
Debt - Narrative (Details)	Aug. 01, 2025 USD ($) monthly_installment	Jun. 05, 2025 USD ($)	Aug. 11, 2023	Nov. 25, 2021	Oct. 30, 2020 USD ($)	Sep. 30, 2025 USD ($)	Sep. 30, 2024 USD ($)	Dec. 31, 2022	Sep. 30, 2025 USD ($) financing_arrangement	Sep. 30, 2024 USD ($)
Debt Instrument [Line Items]
Income (loss) from sale-leaseback transfer of tax benefits						$ 0	$ 0		$ 10,188,000	$ 0
Number of sale leaseback financing arrangements \| financing_arrangement									1
Minimum
Debt Instrument [Line Items]
Imputed interest rate for financing obligation									7.20%
Incremental borrowing rate for deferred investment tax credit gain									4.50%
Maximum
Debt Instrument [Line Items]
Imputed interest rate for financing obligation									11.50%
Incremental borrowing rate for deferred investment tax credit gain									5.60%
Disposal Group, Disposed of by Sale, Not Discontinued Operations \| GREC Entity HoldCo
Debt Instrument [Line Items]
Total cash proceeds from divestiture		$ 46,300,000
Repayments of debt		$ 32,500,000
GREC Entity HoldCo \| Secured Debt
Debt Instrument [Line Items]
Basis spread on variable rate (in percentage)				1.85%					1.85%
Midway III Manager LLC \| Secured Debt
Debt Instrument [Line Items]
Basis spread on variable rate (in percentage)								1.73%	1.73%
GB Solar TE 2000 \| Secured Debt
Debt Instrument [Line Items]
Maximum borrowing capacity					$ 19,600,000
GB Solar TE 2000 \| Secured Debt \| Variable Rate, First Timeframe
Debt Instrument [Line Items]
Basis spread on variable rate (in percentage)					1.88%
GB Solar TE 2000 \| Secured Debt \| Variable Rate, Second Timeframe
Debt Instrument [Line Items]
Basis spread on variable rate (in percentage)					2.00%
GB Solar TE 2000 \| Secured Debt \| Variable Rate, Increase Per Annum
Debt Instrument [Line Items]
Increase to interest rate					0.13%
Greenbacker Renewable Energy Company LLC Premium Loan \| Premium Financing Loan
Debt Instrument [Line Items]
Interest rate	7.15%
Payments due, monthly	$ 400,000
Number of monthly installments (in monthly installments) \| monthly_installment	9
Face amount of debt	$ 4,200,000
Conic Manager LLC \| Secured Debt
Debt Instrument [Line Items]
Basis spread on variable rate (in percentage)									1.75%
GREC Warehouse Holdings I LLC \| Line of Credit \| Revolving Credit Facility
Debt Instrument [Line Items]
Basis spread on variable rate (in percentage)									2.03%
GREC Warehouse Holdings I LLC \| Line of Credit \| Variable Rate, First Timeframe \| Revolving Credit Facility
Debt Instrument [Line Items]
Basis spread on variable rate (in percentage)			2.03%
GREC Warehouse Holdings I LLC \| Line of Credit \| Variable Rate, Second Timeframe \| Revolving Credit Facility
Debt Instrument [Line Items]
Basis spread on variable rate (in percentage)			2.28%

Greenbacker Renewable Energy Co LLC 10-Q