Ameresco, Inc. Annual report pursuant to Section 13 and 15(d)

Annual report pursuant to Section 13 and 15(d)

Long-Term Debt - Construction and Term Loans (Details)

Long-Term Debt - Construction and Term Loans (Details)			1 Months Ended		12 Months Ended				13 Months Ended
Long-Term Debt - Construction and Term Loans (Details)	Dec. 22, 2016 USD ($)	Aug. 04, 2016 USD ($) bank	Jan. 31, 2017 USD ($) project	Oct. 31, 2012 USD ($) bank	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Mar. 31, 2010 USD ($)	Jun. 30, 2017 USD ($)	Apr. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Nov. 18, 2016 USD ($)	Nov. 01, 2016 USD ($)	Sep. 30, 2015 USD ($)	Oct. 03, 2011 USD ($)	Mar. 31, 2011 USD ($)	Feb. 28, 2009 USD ($)	Jan. 30, 2006 USD ($) Tranche
Debt Instrument [Line Items]
Long-term debt value, carrying value					$ 202,168,000	$ 165,413,000
Payments on long-term debt					$ 54,164,000	14,014,000	$ 12,392,000
Number of projects acquired \| project			2
6.345% term loans
Debt Instrument [Line Items]
Stated interest rate																			6.345%
Term loan \| 6.345% term loans
Debt Instrument [Line Items]
Original principal amount																			$ 3,240,000
Effective interest rate					3.693%
Term loan \| Variable rate construction to term loan payable in quarterly installments through December 2024
Debt Instrument [Line Items]
Original principal amount																			$ 17,156,000
Number of tranches \| Tranche																			2
Long-term debt value, carrying value					$ 8,757,000	10,139,000
Term loan \| 6.345% term loan payable in semi-annual installments through June 2024
Debt Instrument [Line Items]
Stated interest rate					6.345%
Original principal amount																			$ 13,081,000
Long-term debt value, carrying value					$ 8,295,000	9,096,000
Effective interest rate					3.443%
Term loan \| 6.345% term notes payable in semi annual installments Due February 2021 and June 2024
Debt Instrument [Line Items]
Long-term debt value, carrying value					$ 9,515,000	10,578,000
Term loan \| Variable-rate construction and term loans due 2024
Debt Instrument [Line Items]
Original principal amount									$ 27,868,000
Payments on long-term debt								$ 3,712,000
Term loan \| 6.500% term loan
Debt Instrument [Line Items]
Stated interest rate					6.50%
Original principal amount					$ 755,000
Long-term debt value, carrying value					$ 0	110,000
Term loan \| 7.250% term loan
Debt Instrument [Line Items]
Stated interest rate					7.25%												7.25%
Original principal amount																	$ 5,500,000
Long-term debt value, carrying value					$ 2,218,000	2,651,000
Term loan \| 6.110% construction and term loan
Debt Instrument [Line Items]
Stated interest rate					6.11%											6.11%
Original principal amount																$ 7,380,000
Long-term debt value, carrying value					$ 4,551,000	4,591,000
Term loan \| Variable rate construction to term loan payable in quarterly installments through June 2028
Debt Instrument [Line Items]
Original principal amount				$ 47,234,000
Long-term debt value, carrying value					$ 32,711,000	35,679,000
Effective interest rate					4.70%
Debt instrument, number of banks \| bank				2
Term loan \| Variable-rate construction and term loans due 2023
Debt Instrument [Line Items]
Long-term debt value, carrying value					$ 18,734,000
Term loan \| 4.950% term loan
Debt Instrument [Line Items]
Stated interest rate		4.95%
Original principal amount		$ 4,837,000
Long-term debt value, carrying value					$ 4,605,000	4,616,000
Debt instrument, number of banks \| bank		2
Term loan \| 8.750% construction loan
Debt Instrument [Line Items]
Stated interest rate					8.75%									8.75%
Original principal amount														$ 9,500,000
Long-term debt value, carrying value					$ 0	3,140,000
Long-term debt, gross					0
Term loan \| Variable rate construction loan payable, due June 2018
Debt Instrument [Line Items]
Original principal amount													$ 35,000,000
Long-term debt value, carrying value					$ 1,721,000	7,008,000
Effective interest rate					6.75%
Term loan \| 13.000% construction loan payable, due May 2017
Debt Instrument [Line Items]
Stated interest rate	13.00%				13.00%
Original principal amount	$ 10,694,000
Long-term debt value, carrying value					$ 0	9,503,000
Subjective acceleration clause, repayment period	60 days
Term loan \| 13.000% term loan, facility one
Debt Instrument [Line Items]
Stated interest rate			13.00%
Original principal amount			$ 3,823,000
Term loan \| 13.000% term loan, facility two
Debt Instrument [Line Items]
Original principal amount			$ 4,008,000
Term loan \| Fixed rate construction term loan 2017
Debt Instrument [Line Items]
Original principal amount												$ 4,300,000
Long-term debt, gross					$ 4,258,000
Term loan \| Fixed rate construction term loan 2017, construction phase
Debt Instrument [Line Items]
Stated interest rate												5.50%
Term loan \| 5.000% construction to term loan payable in quarterly installments through March 2028
Debt Instrument [Line Items]
Stated interest rate					5.00%							5.00%
Long-term debt value, carrying value					$ 4,258,000	0
Term loan \| 4.500% construction to term loan payable in monthly installments through April 2027
Debt Instrument [Line Items]
Stated interest rate					4.50%						4.50%
Long-term debt value, carrying value					$ 13,325,000	0
Long-term debt, gross					$ 13,325,000
Construction loan agreement, maximum amount											$ 24,823,000
Term loan \| 5.610% term loan payable in quarterly installments through February 2034
Debt Instrument [Line Items]
Stated interest rate					5.61%						5.61%
Original principal amount											$ 3,151,000
Long-term debt value, carrying value					$ 3,128,000	0
Long-term debt, gross					3,128,000
Term loan \| Variable rate term loan payable in semi-annual installments through December 2027
Debt Instrument [Line Items]
Original principal amount										$ 14,034,000
Long-term debt value, carrying value					14,034,000	0
Long-term debt, gross					$ 14,100,000
Debt interest rate					4.04%
Variable rate construction to term loan \| Variable rate construction to term loan payable in quarterly installments through December 2024
Debt Instrument [Line Items]
Effective interest rate					4.585%
Variable rate construction to term loan \| Variable-rate construction and term loans due 2024
Debt Instrument [Line Items]
Original principal amount																		$ 37,906,000
Draws on line of credit									$ 27,868,000
Variable rate construction to term loan \| Variable-rate construction and term loans due 2023
Debt Instrument [Line Items]
Original principal amount															$ 20,746,000
Long-term debt value, carrying value						$ 19,877,000
Effective interest rate					4.193%