Annual report pursuant to Section 13 and 15(d)

Business Segment Information Business Segment Information - Additional Information (Details)

v2.4.1.9
Business Segment Information Business Segment Information - Additional Information (Details)
 12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Federal, State, Provincial and Local Government      
Segment Reporting Information [Line Items]      
Concentration risk percentage 80.00%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_MajorCustomersAxis
= amrc_FederalStateProvincialandLocalGovernmentMember 		80.00%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_MajorCustomersAxis
= amrc_FederalStateProvincialandLocalGovernmentMember 		80.00%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_MajorCustomersAxis
= amrc_FederalStateProvincialandLocalGovernmentMember
Sales Revenue, Net | Customer Concentration Risk      
Segment Reporting Information [Line Items]      
Concentration risk percentage 16.90%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= us-gaap_SalesRevenueNetMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember 		12.30%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= us-gaap_SalesRevenueNetMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember 		11.60%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= us-gaap_SalesRevenueNetMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember