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

Annual report pursuant to Section 13 and 15(d)

Long-Term Debt - Additional Information (Details)

Long-Term Debt - Additional Information (Details) (USD $)	12 Months Ended			0 Months Ended		13 Months Ended	0 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Mar. 12, 2014 fiscal_quarter	Feb. 27, 2007	Mar. 31, 2010	Mar. 31, 2010	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Jun. 30, 2011	Jan. 30, 2006 Tranche	Sep. 28, 2007	Feb. 28, 2009	Mar. 31, 2011	Oct. 03, 2011	Oct. 31, 2012
Line of Credit Facility [Line Items]
Long-term debt value, carrying value	$ 102,292,000us-gaap_LongTermDebt	$ 116,196,000us-gaap_LongTermDebt
Repayments of Long-term Debt	18,392,000us-gaap_RepaymentsOfLongTermDebt	14,669,000us-gaap_RepaymentsOfLongTermDebt	5,587,000us-gaap_RepaymentsOfLongTermDebt
Revolving Credit Facility
Line of Credit Facility [Line Items]
Current borrowing capacity											60,000,000
Additional borrowing capacity											25,000,000
Amount outstanding	5,000,000	0
Number of Consecutive Fiscal Quarters with Waived Compliance Requirements				4
Debt Covenant Minimum EBITDA Reduced Requirement, Remainder of Fiscal Quarter				16,500
Debt Covenant Minimum EBITDA Reduced Requirement, Second Fiscal Quarter				22,000
Debt Covenant Minimum EBITDA Reduced Requirement, Third Fiscal Quarter				24,000
Debt Covenant Minimum EBITDA Reduced Requirement, Fourth Fiscal Quarter				27,000
Debt Covenant, Minimum EBITDA Requirement								2.0	2.25	2.5
Debt Covenant Minimum, Cash Flow to Debt Service Ratio, Remainder of Fiscal Quarter				1.25
Debt Covenant Minimum, Cash Flow to Debt Service Ratio, Second Fiscal Quarter				1.5
Debt Instrument, Increase (Decrease) in Basis Spread on Variable Rate				0.25%
Debt Instrument, Increase (Decrease) in Basis Spread on Prime Rate				0.25%
Senior secured credit facility, due June 2016, interest at varying rates monthly in arrears
Line of Credit Facility [Line Items]
Long-term debt value, carrying value	25,000,000	25,714,000
Term Loan
Line of Credit Facility [Line Items]
Long-term debt value, carrying value	20,000,000
London Interbank Offered Rate (LIBOR) \| Revolving Credit Facility
Line of Credit Facility [Line Items]
Debt Instrument, Prime Rate				0.50%
Debt Instrument, Basis Spread on Variable Rate				2.00%
Notes Payable to Banks \| Term Loan
Line of Credit Facility [Line Items]
Original principal amount											40,000,000
Principal payments due in quarterly installments	1,429,000
8.673% term loan payable in quarterly installments through December 2015 \| Term Loan
Line of Credit Facility [Line Items]
Original principal amount					7,250,000
Long-term debt value, carrying value	0	1,667,000
Principal payments due in quarterly installments					218,000
Stated interest rate					8.673%
Variable rate construction to term loan payable in quarterly installments through December 2024
Line of Credit Facility [Line Items]
Long-term debt value, carrying value	13,638,000	18,558,000
Variable rate construction to term loan payable in quarterly installments through December 2024 \| Variable rate construction to term loan payable in quarterly installments through June 2028
Line of Credit Facility [Line Items]
Effective interest rate	3.483%
Variable rate construction to term loan payable in quarterly installments through December 2024 \| Term Loan
Line of Credit Facility [Line Items]
Original principal amount												17,156,000
Long-term debt value, carrying value	12,436,000	13,251,000
Number of Tranches												2
Variable Rate Construction Term Loan Payable in semi annual installments through February 26, 2021 \| Term Loan
Line of Credit Facility [Line Items]
Effective interest rate	1.983%
Variable Rate Construction Term Loan Payable in semi annual installments through February 26, 2021 \| Term Loan One
Line of Credit Facility [Line Items]
Original principal amount													3,240,000
Stated interest rate													6.345%
Variable Rate Construction Term Loan Payable in semi annual installments through February 26, 2021 \| Minimum \| Term Loan
Line of Credit Facility [Line Items]
Long-term debt value, carrying value	96,000
Variable Rate Construction Term Loan Payable in semi annual installments through February 26, 2021 \| Maximum \| Term Loan
Line of Credit Facility [Line Items]
Long-term debt value, carrying value	275,000
6.345% term loan payable in semi-annual installments through June 2024 \| Term Loan
Line of Credit Facility [Line Items]
Long-term debt value, carrying value	10,468,000	11,059,000
Effective interest rate	1.858%
6.345% term loan payable in semi-annual installments through June 2024 \| Term Loan Two
Line of Credit Facility [Line Items]
Original principal amount													13,081,000
6.345% term loan payable in semi-annual installments through June 2024 \| Minimum \| Term Loan
Line of Credit Facility [Line Items]
Principal payments due in quarterly installments	248,000
6.345% term loan payable in semi-annual installments through June 2024 \| Maximum \| Term Loan
Line of Credit Facility [Line Items]
Principal payments due in quarterly installments	1,179,000
Construction Loans \| Variable rate construction to term loan payable in quarterly installments through June 2028
Line of Credit Facility [Line Items]
Original principal amount														37,906,000
Draws on line of credit						27,868,000
Construction Loans \| Term Loan
Line of Credit Facility [Line Items]
Original principal amount						27,868,000	27,868,000
Principal payments due in quarterly installments							2,424,000
Repayments of Long-term Debt	3,712,000
Construction Loans \| Minimum \| Term Loan
Line of Credit Facility [Line Items]
Principal payments due in quarterly installments	109,000
Construction Loans \| Maximum \| Term Loan
Line of Credit Facility [Line Items]
Principal payments due in quarterly installments	1,149,000
6.500% term loan payable in monthly installments through October 2017 \| Term Loan
Line of Credit Facility [Line Items]
Original principal amount	755,000
Long-term debt value, carrying value	350,000	459,000
Principal payments due in quarterly installments	11,000
Stated interest rate	6.50%
7.250% term loan payable in quarterly installments through March 2021 \| Term Loan
Line of Credit Facility [Line Items]
Original principal amount															5,500,000
Long-term debt value, carrying value	3,746,000	4,258,000
Stated interest rate															7.25%
7.250% term loan payable in quarterly installments through March 2021 \| Minimum \| Term Loan
Line of Credit Facility [Line Items]
Principal payments due in quarterly installments	133,000
7.250% term loan payable in quarterly installments through March 2021 \| Maximum \| Term Loan
Line of Credit Facility [Line Items]
Principal payments due in quarterly installments	171,000
6.110% term loan payable in monthly installments through June 2028 \| Term Loan
Line of Credit Facility [Line Items]
Original principal amount																7,380,000
Long-term debt value, carrying value	6,081,000	7,028,000
Stated interest rate																6.11%
6.110% term loan payable in monthly installments through June 2028 \| Minimum \| Term Loan
Line of Credit Facility [Line Items]
Principal payments due in quarterly installments	0
6.110% term loan payable in monthly installments through June 2028 \| Maximum \| Term Loan
Line of Credit Facility [Line Items]
Principal payments due in quarterly installments	81,000
Three Point Two Three Three Term Loan Payable In Quarterly Installments Due March Two Thousand Twenty [Member] \| Term Loan
Line of Credit Facility [Line Items]
Original principal amount																	47,200,000
Long-term debt value, carrying value	41,041,000	45,261,000
Effective interest rate	3.233%
Three Point Two Three Three Term Loan Payable In Quarterly Installments Due March Two Thousand Twenty [Member] \| Minimum \| Term Loan
Line of Credit Facility [Line Items]
Principal payments due in quarterly installments	389,000
Three Point Two Three Three Term Loan Payable In Quarterly Installments Due March Two Thousand Twenty [Member] \| Maximum \| Term Loan
Line of Credit Facility [Line Items]
Principal payments due in quarterly installments	$ 903,000