Name:	fsp_EffectiveRevisedTexasFranchiseTaxRate
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The portion of the difference between total income tax expense or benefit as reported in the income statement for the period and the expected income tax expense or benefit computed by applying the domestic federal statutory income tax rates to pretax income from continuing operations attributable to the Revised Texas Franchise Tax.

No definition available.

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Data Type:	xbrli:monetaryItemType
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Represents the maximum ownership in all Taxable REIT Subsidiaries that can be held by the entity as a percentage of its assets value to maintain its REIT status.

No definition available.

Name:	fsp_MaximumOwnershipInAllTaxableREITSubsidiariesAsPercentageOfAssetsOfEntityToMaintainREITStatus
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Data Type:	num:percentItemType
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Represents the maximum ownership in all Taxable REIT Subsidiaries that can be held by the entity as a percentage of its assets value when considered together with other non-real estate assets to maintain its REIT status.

No definition available.

Name:	fsp_MaximumOwnershipInAllTaxableREITSubsidiariesAsPercentageOfAssetsOfEntityToMaintainREITStatusIncludingOtherNonRealEstateAssets
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Data Type:	num:percentItemType
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Represents the maximum ownership that the entity can hold as a percentage of the voting power or value of the securities of each issuer which is not a REIT or Taxable REIT Subsidiary.

No definition available.

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Data Type:	num:percentItemType
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Represents the period of statute of limitations for the entity's income tax returns, that remain subject to examination.

No definition available.

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- Details

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The sum of the current income tax expense or benefit and the deferred income tax expense or benefit pertaining to continuing operations.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

-Paragraph 9

-Subparagraph (a),(b)

-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32639-109319

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 109

-Paragraph 45

-Subparagraph a, b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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.(h))

-URI http://asc.fasb.org/extlink&oid=6881521&loc=d3e23780-122690

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph h

-Article 4

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Income Tax Expense (or Benefit)

-URI http://asc.fasb.org/extlink&oid=6515339

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- Details

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Data Type:	xbrli:stringItemType
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The sum of other amounts reflected in the reconciliation of the statutory tax provision (benefit) to the actual tax provision (benefit).

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

-Paragraph 12

-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32687-109319

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

-Paragraph 13

-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32698-109319