Annual report pursuant to Section 13 and 15(d)

Business Acquisitions and Related Transactions - Narrative (Details)

v2.4.1.9
Business Acquisitions and Related Transactions - Narrative (Details) (USD $)
In Thousands, unless otherwise specified
12 Months Ended 1 Months Ended 12 Months Ended 1 Months Ended 12 Months Ended
Dec. 31, 2014
Aug. 31, 2014
Jun. 30, 2013
business
Dec. 31, 2013
Feb. 28, 2013
Jul. 31, 2012
Dec. 31, 2012
Business Acquisition [Line Items]              
Weighted average useful life 8 years 2 months 12 days            
EEX              
Business Acquisition [Line Items]              
Initial cash payment   $ 9,054us-gaap_PaymentsToAcquireBusinessesGross
/ us-gaap_BusinessAcquisitionAxis
= amrc_EEXMember
         
Security deposit with third-party escrow agent   834amrc_BusinessAcquisitionCostOfAcquiredEntitySecurityDepositInEscrow
/ us-gaap_BusinessAcquisitionAxis
= amrc_EEXMember
         
Purchase price 13,904us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_BusinessAcquisitionAxis
= amrc_EEXMember
           
Total fair value of consideration 13,904us-gaap_BusinessCombinationConsiderationTransferred1
/ us-gaap_BusinessAcquisitionAxis
= amrc_EEXMember
           
ESP              
Business Acquisition [Line Items]              
Security deposit with third-party escrow agent     778amrc_BusinessAcquisitionCostOfAcquiredEntitySecurityDepositInEscrow
/ us-gaap_BusinessAcquisitionAxis
= amrc_ESPMember
       
Number of businesses acquired     2us-gaap_NumberOfBusinessesAcquired
/ us-gaap_BusinessAcquisitionAxis
= amrc_ESPMember
       
Purchase price     8,765us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_BusinessAcquisitionAxis
= amrc_ESPMember
10,531us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_BusinessAcquisitionAxis
= amrc_ESPMember
     
Total fair value of consideration       10,531us-gaap_BusinessCombinationConsiderationTransferred1
/ us-gaap_BusinessAcquisitionAxis
= amrc_ESPMember
     
Ennovate              
Business Acquisition [Line Items]              
Security deposit with third-party escrow agent         1,200amrc_BusinessAcquisitionCostOfAcquiredEntitySecurityDepositInEscrow
/ us-gaap_BusinessAcquisitionAxis
= amrc_EnnovateMember
   
Total fair value of consideration         1,766us-gaap_BusinessCombinationConsiderationTransferred1
/ us-gaap_BusinessAcquisitionAxis
= amrc_EnnovateMember
   
FAME              
Business Acquisition [Line Items]              
Initial cash payment           4,487us-gaap_PaymentsToAcquireBusinessesGross
/ us-gaap_BusinessAcquisitionAxis
= amrc_FameFacilitySoftwareSolutionsIncMember
 
Security deposit with third-party escrow agent           900amrc_BusinessAcquisitionCostOfAcquiredEntitySecurityDepositInEscrow
/ us-gaap_BusinessAcquisitionAxis
= amrc_FameFacilitySoftwareSolutionsIncMember
 
Purchase price             4,487us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_BusinessAcquisitionAxis
= amrc_FameFacilitySoftwareSolutionsIncMember
Total fair value of consideration             $ 4,487us-gaap_BusinessCombinationConsiderationTransferred1
/ us-gaap_BusinessAcquisitionAxis
= amrc_FameFacilitySoftwareSolutionsIncMember