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

Annual report pursuant to Section 13 and 15(d)

Long-Term Debt - Narrative (Details)

Long-Term Debt - Narrative (Details) (USD $)	12 Months Ended								12 Months Ended								12 Months Ended						13 Months Ended		0 Months Ended			12 Months Ended																					12 Months Ended
Long-Term Debt - Narrative (Details) (USD $)	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Revolving Credit Facility	Dec. 31, 2011 Revolving Credit Facility	Jun. 30, 2011 Revolving Credit Facility	Dec. 31, 2012 Federal ESPC receivable financing Construction Loans	Dec. 31, 2011 Federal ESPC receivable financing Construction Loans	Dec. 31, 2012 Notes Payable to Banks Term Loan	Dec. 31, 2011 Notes Payable to Banks Term Loan	Jun. 30, 2011 Notes Payable to Banks Term Loan	Dec. 31, 2012 7.299% term note payable in quarterly installments through March 2013 Term Loan	Dec. 31, 2011 7.299% term note payable in quarterly installments through March 2013 Term Loan	Mar. 31, 2011 7.299% term note payable in quarterly installments through March 2013 Term Loan	Dec. 31, 2012 6.90% Term Loan [Member] Term Loan	Mar. 31, 2011 6.90% Term Loan [Member] Term Loan	Dec. 31, 2012 8.673% term loan payable in quarterly installments through December 2015 Term Loan	Dec. 31, 2011 8.673% term loan payable in quarterly installments through December 2015 Term Loan	Feb. 27, 2007 8.673% term loan payable in quarterly installments through December 2015 Term Loan	Dec. 31, 2012 6.345% term loan payable in quarterly installments through February 2021 Term Loan	Dec. 31, 2011 6.345% term loan payable in quarterly installments through February 2021 Term Loan	Dec. 31, 2012 6.345% term loan payable in quarterly installments through February 2021 Term Loan Two	Mar. 31, 2010 Construction Loans Variable rate construction to term loan payable in quarterly installments through June 30, 2028	Feb. 28, 2009 Construction Loans Variable rate construction to term loan payable in quarterly installments through June 30, 2028	Mar. 31, 2010 Construction Loans Term Loan	Dec. 31, 2012 Construction Loans Term Loan	Dec. 31, 2011 Construction Loans Term Loan	Dec. 31, 2012 6.500% term loan payable in monthly installments through October 2017 Term Loan	Dec. 31, 2011 6.500% term loan payable in monthly installments through October 2017 Term Loan	Dec. 31, 2012 7.250% term loan payable in monthly installments through March 2021 Term Loan	Dec. 31, 2011 7.250% term loan payable in monthly installments through March 2021 Term Loan	Mar. 31, 2011 7.250% term loan payable in monthly installments through March 2021 Term Loan	Dec. 31, 2012 6.110% term loan payable in monthly installments through September 2024 Term Loan	Dec. 31, 2011 6.110% term loan payable in monthly installments through September 2024 Term Loan	Mar. 31, 2011 6.110% term loan payable in monthly installments through September 2024 Term Loan	Dec. 31, 2012 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 30, 2028	Dec. 31, 2011 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 30, 2028	Dec. 31, 2012 Variable rate construction to term loan payable in quarterly installments through December 2024 Term Loan	Dec. 31, 2011 Variable rate construction to term loan payable in quarterly installments through December 2024 Term Loan	Jan. 30, 2006 Variable rate construction to term loan payable in quarterly installments through December 2024 Term Loan Tranche	Dec. 31, 2012 Variable Rate Construction Term Loan Payable in semi annual installments through February 26, 2021 Term Loan	Dec. 31, 2011 Variable Rate Construction Term Loan Payable in semi annual installments through February 26, 2021 Term Loan	Dec. 31, 2012 Variable Rate Construction Term Loan Payable in semi annual installments through February 26, 2021 Term Loan One	Dec. 31, 2012 6.345% term loan payable in quarterly installments through June 2024 Term Loan	Dec. 31, 2011 6.345% term loan payable in quarterly installments through June 2024 Term Loan	Sep. 28, 2007 6.345% term loan payable in quarterly installments through June 2024 Term Loan Two	Dec. 31, 2012 Variable rate construction to term loan payable in quarterly installments through June 30, 2028 Term Loan	Dec. 31, 2011 Variable rate construction to term loan payable in quarterly installments through June 30, 2028 Term Loan	Dec. 31, 2012 Minimum Federal ESPC receivable financing Construction Loans	Dec. 31, 2012 Minimum 7.299% term note payable in quarterly installments through March 2013 Term Loan	Dec. 31, 2012 Minimum Construction Loans Term Loan	Dec. 31, 2012 Minimum 7.250% term loan payable in monthly installments through March 2021 Term Loan	Dec. 31, 2012 Minimum 6.110% term loan payable in monthly installments through September 2024 Term Loan	Dec. 31, 2012 Minimum 6.345% term loan payable in quarterly installments through June 2024 Term Loan	Dec. 31, 2012 Maximum Federal ESPC receivable financing Construction Loans	Dec. 31, 2012 Maximum 7.299% term note payable in quarterly installments through March 2013 Term Loan	Dec. 31, 2012 Maximum Construction Loans Term Loan	Dec. 31, 2012 Maximum 7.250% term loan payable in monthly installments through March 2021 Term Loan	Dec. 31, 2012 Maximum 6.110% term loan payable in monthly installments through September 2024 Term Loan	Dec. 31, 2012 Maximum 6.345% term loan payable in quarterly installments through June 2024 Term Loan
Line of Credit Facility [Line Items]
Discount rate																																																	5.06%						8.38%
Current borrowing capacity						$ 60,000,000
Additional borrowing capacity						25,000,000
Amount outstanding				0	5,000,000				32,857,143	37,142,858
Original principal amount											40,000,000			10,000,000		9,500,000			7,250,000					37,905,983	27,867,627			754,587				5,500,089			7,380,068					17,156,395			3,239,734			13,080,607	47,200,000
Number of Tranches																																								2
Draws on line of credit	(9,285,713)	42,142,858	(19,915,218)																				27,867,627
Stated interest rate												7.299%			6.90%		8.673%					6.345%						6.50%		7.25%			6.11%										6.345%
Principal payments due in quarterly installments									1,428,571								217,500								2,424,302			11,312																						597,000	206,211	120,981	20,502	201,288		638,500	1,239,133	170,902	195,038	1,178,885
Effective interest rate																										2.112%																					3.32%							3.561%
Long-term debt value, carrying value	$ 214,374,850	$ 207,965,571					$ 92,957,447	$ 110,000,993				$ 638,000	$ 1,874,000				$ 2,535,649	$ 3,405,649		$ 2,395,034	$ 2,580,069					$ 20,517,563	$ 22,405,384	$ 553,462	$ 657,554	$ 4,745,850	$ 5,199,779		$ 7,778,390	$ 7,609,681		$ 20,517,563	$ 22,405,384	$ 13,991,346	$ 14,669,673		$ 93,037	$ 275,461		$ 11,596,312	$ 12,089,604		$ 37,800,000	$ 0