Annual report pursuant to Section 13 and 15(d)

Goodwill and Intangible Assets - Intangible Assets (Details)

v2.4.1.9
Goodwill and Intangible Assets - Intangible Assets (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2014
Dec. 31, 2013
Finite-Lived Intangible Assets [Line Items]    
Gross Carrying Amount $ 27,642us-gaap_FiniteLivedIntangibleAssetsGross $ 22,056us-gaap_FiniteLivedIntangibleAssetsGross
Accumulated Amortization 16,404us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization 11,803us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization
Intangible assets, net 11,238us-gaap_FiniteLivedIntangibleAssetsNet 10,253us-gaap_FiniteLivedIntangibleAssetsNet
Customer contracts    
Finite-Lived Intangible Assets [Line Items]    
Gross Carrying Amount 8,103us-gaap_FiniteLivedIntangibleAssetsGross
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= us-gaap_CustomerContractsMember
7,684us-gaap_FiniteLivedIntangibleAssetsGross
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= us-gaap_CustomerContractsMember
Accumulated Amortization 6,911us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= us-gaap_CustomerContractsMember
5,349us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= us-gaap_CustomerContractsMember
Customer relationships    
Finite-Lived Intangible Assets [Line Items]    
Gross Carrying Amount 12,792us-gaap_FiniteLivedIntangibleAssetsGross
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= us-gaap_CustomerRelationshipsMember
8,200us-gaap_FiniteLivedIntangibleAssetsGross
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= us-gaap_CustomerRelationshipsMember
Accumulated Amortization 4,562us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= us-gaap_CustomerRelationshipsMember
2,923us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= us-gaap_CustomerRelationshipsMember
Non-compete agreements    
Finite-Lived Intangible Assets [Line Items]    
Gross Carrying Amount 3,402us-gaap_FiniteLivedIntangibleAssetsGross
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= us-gaap_NoncompeteAgreementsMember
3,230us-gaap_FiniteLivedIntangibleAssetsGross
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= us-gaap_NoncompeteAgreementsMember
Accumulated Amortization 2,725us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= us-gaap_NoncompeteAgreementsMember
1,872us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= us-gaap_NoncompeteAgreementsMember
Technology    
Finite-Lived Intangible Assets [Line Items]    
Gross Carrying Amount 2,794us-gaap_FiniteLivedIntangibleAssetsGross
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= amrc_TechnologyMember
2,386us-gaap_FiniteLivedIntangibleAssetsGross
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= amrc_TechnologyMember
Accumulated Amortization 1,767us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= amrc_TechnologyMember
1,299us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= amrc_TechnologyMember
Trade names    
Finite-Lived Intangible Assets [Line Items]    
Gross Carrying Amount 551us-gaap_FiniteLivedIntangibleAssetsGross
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= us-gaap_TradeNamesMember
556us-gaap_FiniteLivedIntangibleAssetsGross
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= us-gaap_TradeNamesMember
Accumulated Amortization $ 439us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= us-gaap_TradeNamesMember
$ 360us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= us-gaap_TradeNamesMember