Debt Instrument Extension Period

No definition available.

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- Definition

Line of credit facility covenant compliance leverage ratio for two consecutive quarters.

+ References

No definition available.

+ Details

Name:	ahh_LineOfCreditFacilityCovenantComplianceLeverageRatioConsecutiveQuarters
Namespace Prefix:	ahh_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the number of consecutive quarters required for line of credit facility covenant compliance leverage ratio.

+ References

No definition available.

+ Details

Name:	ahh_LineOfCreditFacilityCovenantComplianceLeverageRatioNumberOfConsecutiveQuarters
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Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Line of credit facility covenant, investment to asset value.

+ References

No definition available.

+ Details

Name:	ahh_LineOfCreditFacilityCovenantInvestmentToAssetValue
Namespace Prefix:	ahh_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the maximum number of times the maximum leverage ratio of can be increased during the term of the credit facility.

+ References

No definition available.

+ Details

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Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentLineItems
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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.16)
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.16)
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 19, 20, 22
-Article 5

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The effective interest rate at the end of the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd
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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The cash inflow from borrowings to finance the cost of construction.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3255-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Financing Activities
-URI http://asc.fasb.org/extlink&oid=6513228

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of cash inflow from contractual arrangement with the lender, including but not limited to, letter of credit, standby letter of credit and revolving credit arrangements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Financing Activities
-URI http://asc.fasb.org/extlink&oid=6513228

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3255-108585

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(f))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

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- Details

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- Details

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- Details

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- Details

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- Details

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- Details

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- Details

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Indebtedness - Additional Information (Details)		6 Months Ended
Indebtedness - Additional Information (Details)	Feb. 25, 2016 leverage_ratio_increase	Jun. 30, 2016 USD ($)	May 13, 2016 USD ($)	Mar. 31, 2016 USD ($)	Feb. 20, 2015 USD ($)
Construction Loans
Indebtedness
Borrowings under construction loans		$ 28,200,000
Operating Partnership \| Unsecured Debt \| New Credit Facility
Indebtedness
Aggregate capacity under the credit facility				$ 250,000,000.0	$ 200,000,000.0
Financial covenant, leverage ratio consecutive quarters following any significant acquisition	0.65
Financial covenant, number of consecutive quarters maintaining leverage ratio following any significant acquisition	6 months
Financial covenant, investments to total asset value (as a percent)	10.00%
Financial covenant, maximum number of times maximum leverage ratio can increase \| leverage_ratio_increase	2
Operating Partnership \| Revolving Credit Facility \| Unsecured Debt \| New Credit Facility
Indebtedness
Aggregate capacity under the credit facility					150,000,000.0
Interest rate on credit facility as of end of period (as a percent)		2.21%
Revolving credit facility, extension option (in years)		1 year
Credit facility, amount outstanding		$ 107,000,000
Operating Partnership \| Revolving Credit Facility \| Unsecured Debt \| New Credit Facility \| Minimum \| LIBOR
Indebtedness
Stated interest rate, basis spread on variable rate (as a percent)		1.40%
Operating Partnership \| Revolving Credit Facility \| Unsecured Debt \| New Credit Facility \| Maximum \| LIBOR
Indebtedness
Stated interest rate, basis spread on variable rate (as a percent)		2.00%
Operating Partnership \| Revolving Credit Facility \| Secured Debt \| Prior Credit Facility
Indebtedness
Aggregate capacity under the credit facility			$ 155,000,000.0
Operating Partnership \| Term Loan Facility \| Unsecured Debt \| New Credit Facility
Indebtedness
Aggregate capacity under the credit facility					$ 50,000,000.0
Interest rate on credit facility as of end of period (as a percent)		2.16%
Credit facility, amount outstanding				$ 100,000,000
Amount borrowed under credit facility		$ 100,000,000
Operating Partnership \| Term Loan Facility \| Unsecured Debt \| New Credit Facility \| Minimum \| LIBOR
Indebtedness
Stated interest rate, basis spread on variable rate (as a percent)		1.35%
Operating Partnership \| Term Loan Facility \| Unsecured Debt \| New Credit Facility \| Maximum \| LIBOR
Indebtedness
Stated interest rate, basis spread on variable rate (as a percent)		1.95%