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Related Party Transactions - Additional Information (Detail) (USD $)
12 Months Ended 0 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Nov. 20, 2014
May 22, 2013
May 13, 2013
Related Party Transaction [Line Items]            
Revenue from contracts with affiliated entities $ 5,300,000us-gaap_RevenueFromRelatedParties $ 45,000,000us-gaap_RevenueFromRelatedParties $ 17,400,000us-gaap_RevenueFromRelatedParties      
Operating Margin 46,903,000us-gaap_GrossProfit 42,074,000us-gaap_GrossProfit 40,832,000us-gaap_GrossProfit      
Fees from contracts with affiliated entities 500,000us-gaap_RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty          
Operating Partnership [Member]            
Related Party Transaction [Line Items]            
Amount paid under tax protection agreements       1,300,000us-gaap_PaymentsOfDistributionsToAffiliates
/ dei_LegalEntityAxis
= ahh_OperatingPartnershipMember
47,600,000us-gaap_PaymentsOfDistributionsToAffiliates
/ dei_LegalEntityAxis
= ahh_OperatingPartnershipMember
 
Operating Partnership [Member] | Maximum [Member]            
Related Party Transaction [Line Items]            
Future sale period for properties           7 years
Future sale period for properties in limited number of cases           10 years
General Contracting and Real Estate Services [Member]            
Related Party Transaction [Line Items]            
Operating Margin $ 300,000us-gaap_GrossProfit
/ us-gaap_RelatedPartyTransactionAxis
= ahh_GeneralContractingAndRealEstateServicesMember
$ 1,500,000us-gaap_GrossProfit
/ us-gaap_RelatedPartyTransactionAxis
= ahh_GeneralContractingAndRealEstateServicesMember
$ 1,200,000us-gaap_GrossProfit
/ us-gaap_RelatedPartyTransactionAxis
= ahh_GeneralContractingAndRealEstateServicesMember