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

No definition available.

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

- Definition

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

+ References

No definition available.

+ Details

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

- Definition

Represents number of leases executed during the reporting period.

+ References

No definition available.

+ Details

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

- Definition

Represents committed expenditures for operating leases executed during the period.

+ References

No definition available.

+ Details

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

- Definition

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

+ References

No definition available.

+ Details

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

- Definition

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

+ References

No definition available.

+ Details

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

- Definition

Represents the expected cost of expansion during the current period.

+ References

No definition available.

+ Details

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

- Definition

Represents the weighted average lease term of operating leases.

+ References

No definition available.

+ Details

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

- Definition

Amount of interest capitalized during the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Allowance for Funds Used during Construction
-URI http://asc.fasb.org/extlink&oid=6504829

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6450988&loc=d3e26243-108391

+ Details

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

- Definition

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

+ References

No definition available.

+ Details

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

- Definition

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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.1(d))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

+ Details

Name:	us-gaap_RealEstateInvestmentPropertyAtCost
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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

- Details

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

- Details

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Real Estate Properties - Narrative (Details) $ in Thousands	3 Months Ended
Real Estate Properties - Narrative (Details) $ in Thousands	Mar. 31, 2017 USD ($) ft² lease building property	Dec. 31, 2016 USD ($)	Mar. 31, 2016 building property
Real Estate Properties [Line Items]
Number of properties \| property	74
Number of buildings \| building	96
Carrying value of real estate properties	$ 1,909,506	$ 1,888,760
Number of leases entered \| lease	12
Rentable square feet (in feet) \| ft²	360,103
Weighted average lease term	10 years 7 months 6 days
Expenditures committed on leases	$ 2,241
Committed but unspent tenant related obligations estimated	24,800
Square foot expansion cost	10,138
Interest costs capitalized	$ 61
Continuing operations
Real Estate Properties [Line Items]
Number of properties \| property	74
Number of buildings \| building	96
Carrying value of real estate properties	$ 1,909,506
Discontinued operations
Real Estate Properties [Line Items]
Number of properties \| property	1		1
Number of buildings \| building	1		1
Property held for sale and classified as discontinued operations	$ 12,260