Summary Of Significant Accounting Policies (Redeemable Noncontrolling Interests) (Details) - USD ($) $ in Thousands		12 Months Ended
Jul. 13, 2022	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Rollforward of Redeemable Noncontrolling Interests
Beginning balance		$ 178,370	$ 213,708
Net income		7,253	6,613	$ 4,296
Contributions		0	2,111	74,530
Other comprehensive (loss) income - change in value of interest rate swaps		(119)	765
Distributions & redemptions		(9,541)	(32,445)
Change in redemption value		7,400	(12,382)
Ending balance		$ 183,363	$ 178,370	$ 213,708
Redeemable Noncontrolling Interests \| Plaza El Segundo
Rollforward of Redeemable Noncontrolling Interests
Redeemable noncontrolling interest purchased	21.80%
Payments for repurchase of redeemable noncontrolling interest	$ 23,600
Ownership interest subsequent to redemption	100.00%

Contributions from redeemable noncontrolling interests

No definition available.

Name:	frt_ContributionsFromRedeemableNoncontrollingInterests
Namespace Prefix:	frt_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Other Comprehensive Income (Loss) Attributable to Redeemable Noncontrolling Interests

+ References

No definition available.

+ Details

Name:	frt_OtherComprehensiveIncomeLossAttributableToRedeemableNoncontrollingInterests
Namespace Prefix:	frt_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Ownership interest subsequent to redemption

+ References

No definition available.

+ Details

Name:	frt_OwnershipInterestSubsequentToRedemption
Namespace Prefix:	frt_
Data Type:	dtr-types1:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Redeemable noncontrolling interest, Decrease from Distributions and Purchases to redeemable noncontrolling interest holders

+ References

No definition available.

+ Details

Name:	frt_RedeemableNoncontrollingInterestDecreaseFromDistributionsAndPurchasesToRedeemableNoncontrollingInterestHolders
Namespace Prefix:	frt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

+ Details

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

- Definition

The equity interest of noncontrolling shareholders, partners or other equity holders in consolidated entity.

+ References

No definition available.

+ Details

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

- Definition

Amount of Net Income (Loss) attributable to redeemable noncontrolling interest.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.19)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483621/220-10-S99-2

+ Details

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

- Definition

The cash outflow during the period for redemption of redeemable noncontrolling interests.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 15
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482740/230-10-45-15

+ Details

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

- Definition

As of the reporting date, the aggregate carrying amount of all noncontrolling interests which are redeemable by the (parent) entity (1) at a fixed or determinable price on a fixed or determinable date, (2) at the option of the holder of the noncontrolling interest, or (3) upon occurrence of an event that is not solely within the control of the (parent) entity. This item includes noncontrolling interest holder's ownership (or holders' ownership) regardless of the type of equity interest (common, preferred, other) including all potential organizational (legal) forms of the investee entity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 480
-SubTopic 10
-Subparagraph (12)(c)
-Section S99
-Paragraph 3A
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480244/480-10-S99-3A

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 480
-SubTopic 10
-Subparagraph 14
-Paragraph 3A
-Section S99
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480244/480-10-S99-3A

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 480
-SubTopic 10
-Subparagraph 15
-Paragraph 3A
-Section S99
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480244/480-10-S99-3A

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 480
-SubTopic 10
-Subparagraph (16)(c)
-Paragraph 3A
-Section S99
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480244/480-10-S99-3A

+ Details

Name:	us-gaap_RedeemableNoncontrollingInterestEquityCarryingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of increase (decrease) in temporary equity from changes classified as other.

+ References

No definition available.

+ Details

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

- Details

Name:	srt_OwnershipAxis=frt_RedeemableNoncontrollingInterestsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=frt_PlazaElSegundoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: