Quarterly report pursuant to Section 13 or 15(d)

Document Entity Information

Document Entity Information
3 Months Ended
Sep. 30, 2011
Nov. 04, 2011
Common Class A [Member]
Nov. 04, 2011
Common Class B [Member]
Entity Registrant Name Ameresco, Inc.    
Entity Central Index Key 0001488139    
Current Fiscal Year End Date --12-31    
Entity Filer Category Non-accelerated Filer    
Document Type 10-Q    
Document Period End Date Sep. 30, 2011
Document Fiscal Year Focus 2011    
Document Fiscal Period Focus Q3    
Amendment Flag true    
Amendment Description Re-submit interactive data files for the sole purpose of correcting inaccurate reporting of Pre-tax income of ($1,727,360) under Note 3. Business Acquisitions and Related Transactions    
Common Stock   25,360,711 18,000,000