Represents the optional maximum extension term for ground leases.

No definition available.

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- Definition

Number of ground leases.

+ References

No definition available.

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- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References

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- Definition

Amount of contractual obligation, including but not limited to, long-term debt, capital lease obligations, operating lease obligations, purchase obligations, and other commitments.

+ References

No definition available.

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- Definition

Term of lessee's operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 20
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-Subparagraph (a)(3)
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- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

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- 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

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- 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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- Definition

Number of separate real estate development properties located on land subject to ground leases.

+ References

No definition available.

+ Details

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- Definition

Rental expense for the reporting period incurred under operating leases, including minimum and any contingent rent expense, net of related sublease income.

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-Name Accounting Standards Codification
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Commitments and Contingencies - Additional Information (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017 USD ($) property lease	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Commitments and Contingencies
Line of credit, performance and payment bonds	$ 44.9	$ 40.5
Number of ground leases \| lease	5
Number of properties subject to ground leases \| property	4
Maximum optional ground lease extension term	40 years
Rental Revenues \| Hampton Roads Properties
Commitments and Contingencies
Concentrations of credit risk	53.00%	58.00%	68.00%
Rental Revenues \| Town Center Properties
Commitments and Contingencies
Concentrations of credit risk	38.00%	41.00%	46.00%
Rental Revenues \| Richmond Tower
Commitments and Contingencies
Concentrations of credit risk		1.00%	11.00%
Minimum
Commitments and Contingencies
Lease term	20 years
Maximum
Commitments and Contingencies
Lease term	65 years
Point Street Apartments \| Financial Guarantee \| Letter of Credit
Commitments and Contingencies
Credit facility, amount outstanding	$ 2.1	$ 2.1
Operating Partnership
Commitments and Contingencies
Outstanding letters of credit	$ 2.1	$ 4.1
Group Of Five Construction Customers \| General Contracting and Real Estate Services Revenues
Commitments and Contingencies
Concentrations of credit risk	88.00%	52.00%	15.00%
Group Of Five Construction Customers \| General Contracting and Real Estate Services Segment Profit
Commitments and Contingencies
Concentrations of credit risk	83.00%	43.00%	20.00%
Ground Leases
Commitments and Contingencies
Ground rent expense	$ 2.5	$ 2.0	$ 1.7