XML 48 R37.htm IDEA: XBRL DOCUMENT
v3.25.1

Income Taxes (Details) - USD ($) | 3 Months Ended | 12 Months Ended |  |
--- | --- | --- | --- | ---
Mar. 31, 2025 | Mar. 31, 2024 | Dec. 31, 2017 | Dec. 31, 2024 | Dec. 31, 2023
Income Taxes |  |  |  |  |
Maximum ownership as a percentage of the voting power or value of the securities of each issuer other than REIT or "TRS" | 10.00% |  |  |  |
Maximum ownership of securities in all TRS (as a percent) | 20.00% |  | 25.00% |  |
Maximum ownership of securities in all TRS when considered together with other non-real estate assets (as a percent) | 25.00% |  |  |  |
Gross amount of NOL of TRS |  |  |  | $ 4,900,000 | $ 4,900,000
Period of statute of limitations applicable to the entity's income tax returns | 3 years |  |  |  |
Net operating losses |  |  |  |  |
NOLs expiration period | 20 years |  |  |  |
NOLs expired in the period |  |  |  | 400,000 |
Gross amount of NOLs available to company | $ 95,800,000 |  |  | $ 95,800,000 |
Income Tax Expense |  |  |  |  |
Revised Texas Franchise Tax | 52,000 | $ 58,000 |  |  |
Tax expense | 52,000 | $ 58,000 |  |  |
Deferred income taxes | $ 0 |  |  |  |

X
- Definition 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. + References No definition available. + Details
Name: | fsp_IncomeTaxReconciliationRevisedTexasFranchiseTax
Namespace Prefix: | fsp_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition 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. + References No definition available. + Details
Name: | fsp_MaximumOwnershipInAllTaxableREITSubsidiariesAsPercentageOfAssetsOfEntityToMaintainREITStatus
Namespace Prefix: | fsp_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition 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. + References No definition available. + Details
Name: | fsp_MaximumOwnershipInAllTaxableREITSubsidiariesAsPercentageOfAssetsOfEntityToMaintainREITStatusIncludingOtherNonRealEstateAssets
Namespace Prefix: | fsp_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition 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. + References No definition available. + Details
Name: | fsp_MaximumOwnershipPercentageInEachIssuerOtherThanREITOrTRSToMaintainREITStatus
Namespace Prefix: | fsp_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of operating loss carryforward of TRS, before tax effects, available to reduce future taxable income under enacted tax laws. + References No definition available. + Details
Name: | fsp_OperatingLossCarryForwardsREITSubsidiary
Namespace Prefix: | fsp_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- References No definition available. + Details
Name: | fsp_OperatingLossCarryforwardAbstract
Namespace Prefix: | fsp_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the period after which the net operating losses expire. + References No definition available. + Details
Name: | fsp_OperatingLossCarryforwardsExpirationPeriod
Namespace Prefix: | fsp_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of operating loss carryforward, before tax effects, expired during the period. + References No definition available. + Details
Name: | fsp_OperatingLossCarryforwardsExpiredInPeriod
Namespace Prefix: | fsp_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Represents the period of statute of limitations for the entity's income tax returns, that remain subject to examination. + References No definition available. + Details
Name: | fsp_PeriodOfStatuteOfLimitations
Namespace Prefix: | fsp_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of deferred income tax expense (benefit) pertaining to income (loss) from continuing operations. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 45 -Paragraph 28 -Subparagraph (b) -SubTopic 10 -Topic 230 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482740/230-10-45-28 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08(h)(1)(Note 1)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Name Accounting Standards Codification -Section 50 -Paragraph 9 -Subparagraph (b) -SubTopic 10 -Topic 740 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482685/740-10-50-9 + Details
Name: | us-gaap_DeferredIncomeTaxExpenseBenefit
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_IncomeTaxDisclosureAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 270 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (i) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482964/270-10-50-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 32 -Subparagraph (ee) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482810/280-10-50-32 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 12 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482685/740-10-50-12 Reference 4: http://www.xbrl.org/2003/role/exampleRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 231 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482663/740-10-55-231 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 250 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 9 -Publisher FASB -URI https://asc.fasb.org/1943274/2147483443/250-10-50-9 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 6.I.7) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479360/740-10-S99-1 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Topic 250 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 8 -Publisher FASB -URI https://asc.fasb.org/1943274/2147483443/250-10-50-8 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 10 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482685/740-10-50-10 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 22 -Subparagraph (h) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482810/280-10-50-22 Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04(9)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477250/944-220-S99-1 Reference 11: http://www.xbrl.org/2003/role/disclosureRef -Name Accounting Standards Codification -Section 45 -Paragraph 2 -Subparagraph (a) -SubTopic 20 -Topic 740 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482659/740-20-45-2 Reference 12: http://www.xbrl.org/2003/role/disclosureRef -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08(h)) -SubTopic 10 -Topic 235 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1 + Details
Name: | us-gaap_IncomeTaxExpenseBenefit
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_IncomeTaxExpenseBenefitContinuingOperationsIncomeTaxReconciliationAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of operating loss carryforward, before tax effects, available to reduce future taxable income under enacted tax laws. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482685/740-10-50-3 + Details
Name: | us-gaap_OperatingLossCarryforwards
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant