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

Business Acquisitions and Related Transactions - Additional Information (Details)

v3.19.2

Business Acquisitions and Related Transactions - Additional Information (Details) $ in Thousands	1 Months Ended	6 Months Ended
	Jan. 31, 2019 USD ($)	Jun. 30, 2019	Jun. 30, 2019 Agreement	Jun. 30, 2019 USD ($)	Jun. 30, 2019 project
Business Acquisition [Line Items]
Measurement period adjustment				$ 719
Measurement period adjustment, hold back contingency				398
Number of projects acquired			4		4
Number of projects under definitive agreement to acquire \| Agreement			3
Massachusetts Based Solar Operations And Maintenance Firm
Business Acquisition [Line Items]
Fair value of consideration	$ 1,279
Measurement period adjustment				91
Minimum \| Solar Photovoltaic Projects
Business Acquisition [Line Items]
Estimated useful life		1 year
Maximum \| Solar Photovoltaic Projects
Business Acquisition [Line Items]
Estimated useful life		15 years
U.S. Federal
Business Acquisition [Line Items]
Measurement period adjustment				$ 628

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Amount of increase (decrease) from adjustments after acquisition date under purchase accounting of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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