Name:	gov_AssetsHeldForSaleProperty
Namespace Prefix:	gov_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Amount classified as real estate properties attributable to disposal group held for sale or disposed of.

No definition available.

Name:	gov_DisposalGroupIncludingDiscontinuedOperationRealEstateInvestmentPropertyNet
Namespace Prefix:	gov_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Amount classified as liabilities attributable to property that is held for sale apart from normal operations and anticipated to be sold in less than one year.

No definition available.

Name:	gov_LiabilitiesHeldForSaleProperty
Namespace Prefix:	gov_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

The number of buildings owned as of the balance sheet date.

No definition available.

Name:	gov_NumberOfBuildings
Namespace Prefix:	gov_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

Represents number of leases executed during the reporting period.

No definition available.

Name:	gov_NumberOfOperatingLeaseExecuted
Namespace Prefix:	gov_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Represents committed expenditures for operating leases executed during the period.

No definition available.

Name:	gov_OperatingLeasesCommittedExpendituresOnLeasesExecutedInPeriod
Namespace Prefix:	gov_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Represents the area of leased property related to operating leases executed during the period.

No definition available.

Name:	gov_OperatingLeasesCommittedExpendituresOnLeasesExecutedInPeriodAreaOfLeasedProperty
Namespace Prefix:	gov_
Data Type:	num:areaItemType
Balance Type:	na
Period Type:	duration

Represents committed but unspent tenant related obligations based on executed operating leases as of the balance sheet date.

No definition available.

Name:	gov_OperatingLeasesCommittedExpendituresOnLeasesExecutedInPeriodCommittedButUnspentTenantRelatedObligations
Namespace Prefix:	gov_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Represents the weighted average lease term of operating leases.

No definition available.

Name:	gov_OperatingLeasesWeightedAverageLeaseTerm
Namespace Prefix:	gov_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Represents the aggregate purchase price excluding acquisition costs of real estate properties acquired or agreed to be acquired by the entity.

No definition available.

Name:	gov_RealEstateAggregatePurchasePrice
Namespace Prefix:	gov_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

This element represents the aggregate sales price excluding closing costs, of real estate properties sold by the entity.

No definition available.

Name:	gov_RealEstateAggregateSalesPrice
Namespace Prefix:	gov_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Area of a real estate property.

No definition available.

Name:	us-gaap_AreaOfRealEstateProperty
Namespace Prefix:	us-gaap_
Data Type:	num:areaItemType
Balance Type:	na
Period Type:	instant

Amount classified as accounts, notes and loans receivable attributable to disposal group held for sale or disposed of.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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Name:	us-gaap_DisposalGroupIncludingDiscontinuedOperationAccountsNotesAndLoansReceivableNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Amount classified as other assets attributable to disposal group held for sale or disposed of.

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Name:	us-gaap_DisposalGroupIncludingDiscontinuedOperationOtherAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
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Amount classified as other liabilities attributable to disposal group held for sale or disposed of.

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

- References

No definition available.

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

The difference between the carrying value and the sale price of real estate or properties that were intended to be sold or held for capital appreciation or rental income. This element refers to the gain (loss) included in earnings and not to the cash proceeds of the sale. This element is a noncash adjustment to net income when calculating net cash generated by operating activities using the indirect method.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

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.

No definition available.

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

The increase (decrease) during the period in book value of long-lived assets that the reporting entity plans to sell within one year (or one business cycle).

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Name:	us-gaap_IncreaseDecreaseInAssetsHeldForSale
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The number of real estate properties owned as of the balance sheet date.

No definition available.

Name:	us-gaap_NumberOfRealEstateProperties
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

Future minimum rental payments in aggregate as of the balance sheet date under operating leases.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
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Name:	us-gaap_OperatingLeasesFutureMinimumPaymentsReceivable
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.

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

Future rental payments receivable within one year of the balance sheet date under an operating lease.

Name:	us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Future rental payments receivable within the fifth year from the balance sheet date under an operating lease.

Name:	us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableInFiveYears
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Future rental payments receivable within the fourth year from the balance sheet date under an operating lease.

Name:	us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableInFourYears
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Future rental payments receivable within the third year from the balance sheet date under an operating lease.

Name:	us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableInThreeYears
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Future rental payments receivable within the second year from the balance sheet date under an operating lease.

Name:	us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableInTwoYears
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Future minimum lease payments receivable under operating leases for periods greater than five years following the balance sheet date.

Name:	us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableThereafter
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Amount of real estate investment property which may include the following: (1) land available-for-sale; (2) land available-for-development; (3) investments in building and building improvements; (4) tenant allowances; (5) developments in-process; (6) rental properties; and (7) other real estate investments.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section S99
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Name:	us-gaap_RealEstateInvestmentPropertyAtCost
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Amount of real estate investment property, net of accumulated depreciation, which may include the following: (1) land available-for-sale; (2) land available-for-development; (3) investments in building and building improvements; (4) tenant allowances; (5) developments in-process; (6) rental properties; and (7) other real estate investments.

Name:	us-gaap_RealEstateInvestmentPropertyNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Name:	us-gaap_StatementOperatingActivitiesSegmentAxis=us-gaap_SegmentContinuingOperationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_StatementOperatingActivitiesSegmentAxis=us-gaap_SegmentDiscontinuedOperationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_StatementGeographicalAxis=gov_SacramentoCaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=us-gaap_SeriesOfIndividuallyImmaterialBusinessAcquisitionsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis=gov_OfficeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_DisposalGroupClassificationAxis=us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_StatementGeographicalAxis=gov_RiverdaleMDMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=gov_OneBuildingAcquisitionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	gov_RealEstateLeasedLocationAndByAuthoritiesByTypeAxis=gov_USGovernmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_StatementGeographicalAxis=gov_SavannahGAMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_DisposalGroupClassificationAxis=us-gaap_DiscontinuedOperationsHeldforsaleMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_StatementGeographicalAxis=gov_FallsChurchVAMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: