Annual debt service savings.

No definition available.

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Balance Type:	credit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the old debt agreement.

+ References

No definition available.

+ Details

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Data Type:	dtr-types:percentItemType
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Period Type:	instant

- Definition

Debt instrument new face amount.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Paid net cash outlays from sale.

+ References

No definition available.

+ Details

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

- Definition

Proceeds from anticipated to be released from held in escrow.

+ References

No definition available.

+ Details

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Namespace Prefix:	frevsob_
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Balance Type:	credit
Period Type:	duration

- Definition

Proceeds from sale of business.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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 http://asc.fasb.org/extlink&oid=79982066&loc=d3e1392-128463

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Balance Type:	na
Period Type:	instant

- Definition

Date when the debt instrument is scheduled to be fully repaid, in YYYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(2))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1B
-Subparagraph (d)
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Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)
-URI http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258

+ Details

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- Definition

The designation of funds furnished by a borrower to a lender to assure future payments of the borrower's real estate taxes and insurance obligations with respect to a mortgaged property. Escrow deposits may be made for a variety of other purposes such as earnest money and contingent payments. This element excludes replacement reserves which are an escrow separately provided for within the US GAAP taxonomy.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.10)
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 954
-SubTopic 440
-Section 50
-Paragraph 1
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=6491277&loc=d3e6429-115629

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of gain (loss) from sale and disposal of integrated set of activities and assets capable of being conducted and managed for purpose of providing return in form of dividend, lower cost, or other economic benefit to investor, owner, member and participant.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3602-108585

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 1B
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109239629&loc=SL4582445-111684

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The amount of expense provided in the period for legal costs incurred on or before the balance sheet date pertaining to resolved, pending or threatened litigation, including arbitration and mediation proceedings.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.3)
-URI http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227

+ Details

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

- Definition

Amount of litigation expense, including but not limited to legal, forensic, accounting, and investigative fees.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The portion of the carrying amount of long-term borrowings outstanding as of the balance sheet date, including current maturities, which accrues interest at a set, unchanging rate.

+ References

No definition available.

+ Details

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- Definition

Amount of cash outflow for costs that are essential to originate the lease and would not otherwise have been incurred without the lease agreement. Amount includes, but is not limited to, cash outflows to evaluate the lessee's credit condition, guarantees, and collateral and cash outflows for costs incurred in negotiating, processing, and executing the lease agreement.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=120321790&loc=d3e6927-128479

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3213-108585

+ Details

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Balance Type:	credit
Period Type:	duration

- Definition

The cash outflow during the period from the repayment of aggregate short-term and long-term debt. Excludes payment of capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3291-108585

+ Details

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Period Type:	duration

- Definition

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

+ References

No definition available.

+ Details

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- Details

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- Details

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- Details

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- Details

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- Details

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Subsequent events (Details) - USD ($)			1 Months Ended		12 Months Ended
Subsequent events (Details) - USD ($)	Jan. 10, 2022	Jan. 07, 2022	Dec. 30, 2021	Nov. 22, 2021	Oct. 31, 2021	Oct. 31, 2020	Oct. 31, 2019
Subsequent Event [Line Items]
Available to draw					$ 279,000	$ 250,000	$ 569,000
Legal fees					2,282,000	957,000
Escrow deposit amount					1,814,000	1,249,000	2,135,000
Repayments of mortgage debt					162,000	162,000
Expense incurred					$ 0	$ 4,606,000	$ 1,416,000
Subsequent Event [Member] \| Purchase and Sale Agreement [Member] \| FREIT Maryland owned 100% of its subsidiary [Member]
Subsequent Event [Line Items]
Percentage of ownership interest				100.00%
Subsequent Event [Member] \| Purchase and Sale Agreement [Member] \| Grande Rotunda [Member]
Subsequent Event [Line Items]
Percentage of ownership interest				60.00%
Subsequent Event [Member] \| Purchase and Sale Agreement [Member] \| Damascus Centre [Member]
Subsequent Event [Line Items]
Percentage of ownership interest				70.00%
Subsequent Event [Member] \| Purchase and Sale Agreement of Rotunda Property [Member]
Subsequent Event [Line Items]
Purchase price			$ 191,080,598	$ 2,723,000
Escrow deposit amount			14,026,401	15,526,731
Proceeds from sale			68,700,000
Repayments of mortgage debt			116,500,000
Expense incurred			30,900,000
Gain from sale			52,000,000
Proceeds from anticipated to be released from held in escrow			8,200,000
Subsequent Event [Member] \| Purchase and Sale Agreement of Westridge Square Property [Member]
Subsequent Event [Line Items]
Purchase price		$ 20,984,604
Escrow deposit amount		1,015,396
Repayments of mortgage debt		21,100,000
Gain from sale		8,700,000
Proceeds from anticipated to be released from held in escrow		700,000
Paid net cash outlays from sale		$ 700,000
Subsequent Event [Member] \| Purchase and Sale Agreement of Damascus Property [Member]
Subsequent Event [Line Items]
Purchase price	$ 36,685,067
Escrow deposit amount	484,934
Proceeds from sale	16,900,000
Repayments of mortgage debt	18,200,000
Gain from sale	10,100,000
Proceeds from anticipated to be released from held in escrow	$ 400,000
Subsequent Event [Member] \| Minimum [Member] \| Purchase and Sale Agreement of Rotunda Property [Member]
Subsequent Event [Line Items]
Purchase price				248,750,269
Subsequent Event [Member] \| Maximum [Member] \| Purchase and Sale Agreement of Rotunda Property [Member]
Subsequent Event [Line Items]
Purchase price				$ 267,000,000
Subsequent Event [Member] \| FREIT Maryland [Member]
Subsequent Event [Line Items]
Fixed rate mortgage loans			14,400,000
Loan amount, new			$ 7,500,000
Maturity date of loan			Feb. 01, 2022
Available to draw			$ 7,500,000
Legal fees			250,000
Annual debt service savings			$ 1,173,000
Subsequent Event [Member] \| FREIT Maryland [Member] \| Minimum [Member]
Subsequent Event [Line Items]
Fixed interest rate on old loan			2.85%
Subsequent Event [Member] \| FREIT Maryland [Member] \| Maximum [Member]
Subsequent Event [Line Items]
Fixed interest rate on old loan			5.37%