Ameresco, Inc. Quarterly report pursuant to Section 13 or 15(d)

Leases - Additional Information (Details) $ in Thousands	3 Months Ended		6 Months Ended
Leases - Additional Information (Details) $ in Thousands	Jun. 30, 2023 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2023 USD ($) project	Jun. 30, 2022 USD ($)
Lessee, Lease, Description [Line Items]
Commitment for future lease payments for leases that do not yet meet the criteria of a ROU asset or liability	$ 10,500		$ 10,500
Lease payments to be made over a period	20 years		20 years
Net amortization expense	$ 57	$ 114	$ 57	$ 114
August 2018 Long Term Finance Liability \| Solar Photovoltaic Projects
Lessee, Lease, Description [Line Items]
Solar PV projects sold \| project			4
Investment fund call option exercise			$ 80,384
August 2018 Long Term Finance Liability \| Solar Photovoltaic Projects \| Revolving Credit Facility \| Line of Credit
Lessee, Lease, Description [Line Items]
Available funding under lending commitment	$ 350,000		$ 350,000
December 2020 Long Term Finance Liability \| Solar Photovoltaic Projects
Lessee, Lease, Description [Line Items]
Solar PV projects sold \| project			3
Investment fund call option exercise			$ 9,201