Annual report pursuant to Section 13 and 15(d)

Document and Entity Information

v3.3.1.900
Document and Entity Information - USD ($)
12 Months Ended
Dec. 31, 2015
Mar. 01, 2016
Jun. 30, 2015
Entity Information [Line Items]      
Entity Registrant Name Ameresco, Inc.    
Entity Central Index Key 0001488139    
Current Fiscal Year End Date --12-31    
Entity Filer Category Accelerated Filer    
Document Type 10-K    
Document Period End Date Dec. 31, 2015    
Document Fiscal Year Focus 2015    
Document Fiscal Period Focus FY    
Amendment Flag false    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Public Float     $ 164,140,259
Class A Common Stock      
Entity Information [Line Items]      
Common Stock   28,769,242  
Class B Common Stock      
Entity Information [Line Items]      
Common Stock   18,000,000