The expense incurred to persons or entities for securing insurance coverage for properties and subsidiaries.

No definition available.

Name:	frevsob_InsuranceCommissionsPaid
Namespace Prefix:	frevsob_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Percentage of management fees of rent collected.

+ References

No definition available.

+ Details

Name:	frevsob_PercentageOfManagementFeesOfRentCollected
Namespace Prefix:	frevsob_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of voting equity interests acquired at the acquisition date in the business combination.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=79982066&loc=d3e1392-128463

+ Details

Name:	us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 45
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=109237563&loc=d3e33749-111570

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(10))
-URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 25
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8813-108599

+ Details

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

- Definition

Amount of expenses related to the managing member or general partner for management of the day-to-day business functions of the limited liability company (LLC) or limited partnership (LP).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

+ Details

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

- Definition

Amount of realized gain (loss) on investment.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04.3(a))
-URI https://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263

+ Details

Name:	us-gaap_RealizedInvestmentGainsLosses
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- 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

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

- Details

Name:	us-gaap_InvestmentTypeAxis=frevsob_FREITsInvestmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=frevsob_SAndACommercialAssociatesLimitedPartnershipMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=frevsob_PierreTowersLlcMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=frevsob_TICAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Investment in tenancy-in-common (Narrative) (Details) - USD ($)	1 Months Ended	3 Months Ended		6 Months Ended
	Feb. 28, 2020	Apr. 30, 2022	Apr. 30, 2021	Apr. 30, 2022	Apr. 30, 2021	Oct. 31, 2021
Schedule of Equity Method Investments [Line Items]
Investment in tenancy-in-common		$ 18,870,000		$ 18,870,000		$ 19,383,000
Loss on investment in tenancy-in-common		32,000	$ 118,000	156,000	$ 145,000
Percentage of management fees of rent collected	5.00%
Management fees		99,000	95,000	197,000	187,000
Insurance commissions		0	$ 0	0	$ 10,000
FREIT’s Investment [Member]
Schedule of Equity Method Investments [Line Items]
Investment in tenancy-in-common		$ 18,900,000		$ 18,900,000		$ 19,400,000
S And A Commercial Associates Limited Partnership [Member]
Schedule of Equity Method Investments [Line Items]
Percentage of ownership interest	65.00%
Pierre Towers, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Percentage of ownership interest	100.00%
TIC Agreement [Member]
Schedule of Equity Method Investments [Line Items]
Percentage of ownership interest	65.00%