Ameresco, Inc. Quarterly report [Sections 13 or 15(d)]

Quarterly report [Sections 13 or 15(d)]

DEBT AND FINANCING LEASE LIABILITIES - Additional Information (Details)

DEBT AND FINANCING LEASE LIABILITIES - Additional Information (Details) $ in Thousands					3 Months Ended
	Mar. 30, 2026 USD ($)	Feb. 03, 2026 USD ($) project	Sep. 26, 2025 USD ($)	Jan. 23, 2025 USD ($)	Mar. 31, 2026 USD ($) energy_asset	Jun. 30, 2025 USD ($)	Mar. 31, 2025 USD ($)	Dec. 31, 2025 USD ($)	Sep. 28, 2023
Debt Instrument [Line Items]
Repayments of secured debt					$ 1,250		$ 14,250
Proceeds from long-term corporate debt financings					45,000		$ 100,000
Letters of credit outstanding					4,087
Senior secured corporate term loans \| Secured Debt
Debt Instrument [Line Items]
Repayments of secured debt				$ 13,000
Long-term debt, gross					$ 138,750			$ 95,000
Term Loan A \| Secured Debt
Debt Instrument [Line Items]
Fixed interest rate, percentage					6.23%
Senior Secured Credit Facility \| Secured Debt
Debt Instrument [Line Items]
Debt issuance costs					$ 2,345
Senior Secured Credit Facility, Term Loan Maturing December 2028 \| Line of Credit
Debt Instrument [Line Items]
Credit facility, periodic payment				$ 1,250
Senior Secured Credit Facility, Term Loan Maturing December 2028 \| Secured Debt
Debt Instrument [Line Items]
Debt issuance costs	$ 131
Interest expense	1,085
Proceeds from long-term corporate debt financings	2,784
Senior Secured Credit Facility, Maturing December 2028 \| Line of Credit
Debt Instrument [Line Items]
Minimum debt service coverage ratio				1.5
Total funded debt to EBITDA covenant ratio				3.5
August 2018 Long Term Finance Liability \| Solar Photovoltaic Projects
Debt Instrument [Line Items]
Solar PV projects sold \| energy_asset					2
Cash proceeds from sale-leaseback of energy assets					$ 4,560
Revolving Credit Facility \| Line of Credit
Debt Instrument [Line Items]
Fixed interest rate, percentage					6.23%
Proceeds used to repay revolving credit facility				$ 180,000
Revolving Credit Facility \| Senior Secured Credit Facility, Revolver, Maturing December 2028 \| Line of Credit
Debt Instrument [Line Items]
Maximum borrowing capacity				225,000
Line of credit facility, accordion feature, increase limit				100,000
Repayments of loan	41,000
Revolving Credit Facility \| Financing Facility, Due September 2040 \| Line of Credit
Debt Instrument [Line Items]
Fixed interest rate, percentage									8.75%
Proceeds used to repay revolving credit facility		$ 97,759
Number of projects \| project		2
Long-term debt, gross		$ 99,900
Long-term debt					$ 440,901
Revolving Credit Facility \| Construction Credit Facility, Due March 2026 \| Line of Credit
Debt Instrument [Line Items]
Fixed interest rate, percentage					5.27%
Long-term debt, gross					$ 20,063
Funds available for borrowing					$ 79,937
Secured Debt \| Senior Secured Credit Facility, Term Loan Maturing December 2028 \| Line of Credit
Debt Instrument [Line Items]
Original principal amount				$ 100,000
Credit facility, periodic payment	1,812
Increase in term loan	$ 45,000
Financing Facility \| Financing Facility, Due September 2040 \| Line of Credit
Debt Instrument [Line Items]
Repayments of loan						$ 7,000
Proceeds to pay off the construction credit facility			$ 25,500
Aggregate true-up payment amount			$ 15,653
Minimum \| Revolving Credit Facility \| Senior secured corporate term loans \| Line of Credit
Debt Instrument [Line Items]
Unused capacity, commitment fee percentage				0.25%
Minimum \| Revolving Credit Facility \| Senior secured corporate term loans \| Base Rate \| Line of Credit
Debt Instrument [Line Items]
Interest rate				0.75%
Minimum \| Revolving Credit Facility \| Senior secured corporate term loans \| Secured Overnight Financing Rate (SOFR) \| Line of Credit
Debt Instrument [Line Items]
Interest rate				1.75%
Maximum \| Revolving Credit Facility \| Senior secured corporate term loans \| Line of Credit
Debt Instrument [Line Items]
Unused capacity, commitment fee percentage				0.375%
Maximum \| Revolving Credit Facility \| Senior secured corporate term loans \| Base Rate \| Line of Credit
Debt Instrument [Line Items]
Interest rate				1.75%
Maximum \| Revolving Credit Facility \| Senior secured corporate term loans \| Secured Overnight Financing Rate (SOFR) \| Line of Credit
Debt Instrument [Line Items]
Interest rate				2.75%