Premiums paid on derivative instruments.

No definition available.

Name:	ahh_PremiumsPaidOnDerivativeInstruments
Namespace Prefix:	ahh_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 12
-Section 13
-Sentence Column B

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

- 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

Cap rate on an interest rate derivative such as an interest rate cap or collar. If market rates exceed the cap rate, a payment or receipt is triggered on the contract.

+ References

No definition available.

+ Details

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

- Definition

Fixed interest rate related to the interest rate derivative.

+ References

No definition available.

+ Details

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- 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

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- 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

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

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 19, 22
-Article 5

+ Details

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

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Namespace Prefix:
Data Type:	na
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- Details

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Namespace Prefix:
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- Details

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- Details

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- Details

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Namespace Prefix:
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Derivative Financial Instruments - Additional Information (Detail) - USD ($) $ in Thousands		12 Months Ended
	Feb. 20, 2015	Dec. 31, 2015	Feb. 25, 2016	Oct. 26, 2015	Jul. 13, 2015	Dec. 31, 2014	Mar. 14, 2014
Derivatives
Interest rate agreement, notional amount		$ 303,639				$ 181,119
Senior Unsecured Term Loan Facility [Member]
Derivatives
Aggregate capacity under the credit facility	$ 50,000
Pay Fixed Interest Rate Swaps [Member]
Derivatives
Interest rate agreement, notional amount		57,093				685
Interest Rate Caps [Member]
Derivatives
Interest rate agreement, notional amount		$ 246,546				$ 180,434
One Month Libor [Member] \| Senior Unsecured Term Loan Facility [Member] \| Minimum
Derivatives
Stated interest rate, basis spread on variable rate	1.35%
One Month Libor [Member] \| Senior Unsecured Term Loan Facility [Member] \| Maximum
Derivatives
Stated interest rate, basis spread on variable rate	1.95%
One Month Libor [Member] \| Pay Fixed Interest Rate Swaps [Member]
Derivatives
Interest rate agreement, notional amount	$ 50,000				$ 6,500
Fixed rate interest rate swap	2.00%				3.05%
LIBOR [Member] \| Senior Unsecured Term Loan Facility [Member] \| Minimum
Derivatives
Stated interest rate, basis spread on variable rate		1.35%
LIBOR [Member] \| Senior Unsecured Term Loan Facility [Member] \| Maximum
Derivatives
Stated interest rate, basis spread on variable rate		1.95%
LIBOR [Member] \| Interest Rate Caps [Member]
Derivatives
Interest rate agreement, notional amount			$ 75,000	$ 75,000			$ 50,000
Interest rate cap agreement, strike price			1.50%	1.25%			1.25%
Interest rate cap agreement, premium			$ 100	$ 100			$ 400