Summary Of Significant Accounting Policies (Derivative Instruments and Mortgage Notes Receivable) (Details) $ in Millions	12 Months Ended
Dec. 31, 2023 USD ($)	Dec. 28, 2023
Derivatives, Fair Value [Line Items]
Number of mortgage receivables	3
Mortgage receivable, net of valuation allowances	$ 9.2
Weighted average interest rate on mortgage note receivables	10.90%
Mortgages Payable
Derivatives, Fair Value [Line Items]
Number of interest rate swap agreements	5
Mortgages Payable \| Hoboken
Derivatives, Fair Value [Line Items]
Number of interest rate swap agreements	2
Fixed interest rate of derivative instrument	3.67%
Mortgages Payable \| Bethesda Row
Derivatives, Fair Value [Line Items]
Number of interest rate swap agreements	3
Fixed interest rate of derivative instrument	5.03%	5.03%
Mortgages Payable \| Assembly Row Hotel
Derivatives, Fair Value [Line Items]
Number of interest rate swap agreements	2
Mortgages Payable \| Assembly Row Hotel \| Through May 2025
Derivatives, Fair Value [Line Items]
Fixed interest rate of derivative instrument	6.39%
Percentage of joint venture's outstanding mortgage debt	100.00%
Mortgages Payable \| Assembly Row Hotel \| June 2025 through May 2028
Derivatives, Fair Value [Line Items]
Fixed interest rate of derivative instrument	6.03%
Percentage of joint venture's outstanding mortgage debt	50.00%

The weighted average interest rate on outstanding financing recievables

No definition available.

Name:	frt_WeightedAverageInterestRateonFinancingReceivable
Namespace Prefix:	frt_
Data Type:	dtr-types1:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of mortgage loans within investment in mortgage loan on real estate by entity with substantial portion of business acquiring and holding investment real estate or interest in real estate.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name Regulation S-X (SX)
-Number 210
-Section 12
-Subsection 29
-Footnote 3
-Publisher SEC

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 948
-SubTopic 310
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.12-29(Footnote 3))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479851/948-310-S99-1

+ Details

Name:	srt_MortgageLoansOnRealEstateNumberOfLoans
Namespace Prefix:	srt_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Fixed interest rate related to the interest rate derivative.

+ References

No definition available.

+ Details

Name:	us-gaap_DerivativeFixedInterestRate
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
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

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

- Definition

Amortized cost, after allowance for credit loss, of financing receivable. Excludes financing receivable covered under loss sharing agreement and net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-04(5)(b))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479617/946-210-S99-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481990/310-10-45-2

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479319/326-20-50-5

+ Details

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

- Definition

Number of interest rate derivative instruments held by the entity at the reporting date.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1B
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480434/815-10-50-1B

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480434/815-10-50-1A

+ Details

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

- Definition

Percentage of an entity's outstanding debt that is designated as a hedged item in cash flow, fair value, or net investment hedge.

+ References

No definition available.

+ Details

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

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_SecuredDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=frt_HobokenMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=frt_BethesdaRowMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=frt_AssemblyRowHotelMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	frt_SpecifiedPeriodPayingFixedInterestRateSwapAxis=frt_ThroughMay2025Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	frt_SpecifiedPeriodPayingFixedInterestRateSwapAxis=frt_June2025ThroughMay2028Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: