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

Derivative Instruments and Hedging Activities- Effects on Statements of Income (Loss) and Consolidated Statements of Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Other expenses, net \| Derivatives Designated as Hedging Instruments \| Interest rate swap instruments
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain Recognized in Net Income	$ (28)	$ (74)	$ (206)	$ (227)