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

Fair Value Measurement - Fair Value of Assets and Liabilities Measured on a Recurring Basis (Details) - Recurring - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Liabilities:
Total liabilities	$ 12,293	$ 7,832
Level 2
Assets:
Total assets	246	213
Level 2 \| Interest rate swap instruments
Assets:
Total assets	0	15
Liabilities:
Liability derivatives	10,882	6,236
Level 2 \| Commodity swap instruments
Assets:
Total assets	246	198
Level 2 \| Interest make-whole provisions
Liabilities:
Liability derivatives	733	918
Level 3
Liabilities:
Contingent consideration	$ 678	$ 678