Consolidated Statements of Capital - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Increase (Decrease) in Partners' Capital [Roll Forward]
Net Income (loss), excluding amounts attributable to redeemable noncontrolling Interests	$ 62,513	$ 61,719	$ 285,031	$ 230,953
Other comprehensive (loss) income - change in fair value of interest rate swaps, excluding portion attributable to redeemable noncontrolling interests	(680)	(4,870)	(2,508)	(1,880)
Purchase of noncontrolling interest	(81)		(7,334)	(12,358)
Contributions from noncontrolling interests				725
Purchase of capped calls				(19,448)
Accumulated Other Comprehensive Income (Loss)
Increase (Decrease) in Partners' Capital [Roll Forward]
Other comprehensive (loss) income - change in fair value of interest rate swaps, excluding portion attributable to redeemable noncontrolling interests	(680)	(4,870)	(2,508)	(1,880)
downREIT OP units
Increase (Decrease) in Partners' Capital [Roll Forward]
Purchase of noncontrolling interest		(675)		(960)
Federal Realty OP LP
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning balance	3,320,100	3,070,813	3,244,144	3,042,159
Net Income (loss), excluding amounts attributable to redeemable noncontrolling Interests	62,513	61,719	285,031	230,953
Other comprehensive (loss) income - change in fair value of interest rate swaps, excluding portion attributable to redeemable noncontrolling interests	(680)	(4,870)	(2,508)	(1,880)
Distributions declared to common unit holders	(97,474)	(93,442)	(287,282)	(275,006)
Distributions on preferred units	(2,008)	(2,008)	(6,024)	(6,024)
Distributions declared to noncontrolling interests in consolidated partnerships, excluding amounts attributable to redeemable noncontrolling interests	(1,110)	(1,293)	(3,334)	(3,183)
Common units issued as a result of common stock issued by Parent Company, net of issuance costs	(86)
Common units issued as a result of common stock issued by Parent Company, net of issuance costs		151,389	54,306	222,319
Common units issued under dividend reinvestment plan	461	476	1,368	1,323
Share-based compensation expense, net of forfeitures	3,691	3,777	11,634	11,952
Common units withheld for employee taxes	(181)	(286)	(4,856)	(4,972)
Purchase of noncontrolling interest				(12,358)
Contributions from noncontrolling interests				725
Purchase of capped calls				(19,448)
Ending balance	3,285,145	3,185,600	3,285,145	3,185,600
Federal Realty OP LP | Preferred Units
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning balance	154,788	154,788	154,788	154,788
Net Income (loss), excluding amounts attributable to redeemable noncontrolling Interests	2,008	2,008	6,024	6,024
Distributions on preferred units	(2,008)	(2,008)	(6,024)	(6,024)
Ending balance	154,788	154,788	154,788	154,788
Federal Realty OP LP | Common Units
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning balance	3,091,329	2,833,788	3,012,066	2,804,669
Net Income (loss), excluding amounts attributable to redeemable noncontrolling Interests	59,641	58,945	275,309	223,647
Distributions declared to common unit holders	(97,474)	(93,442)	(287,282)	(275,006)
Common units issued as a result of common stock issued by Parent Company, net of issuance costs	(86)
Common units issued as a result of common stock issued by Parent Company, net of issuance costs		151,389	54,306	222,319
Common units issued under dividend reinvestment plan	461	476	1,368	1,323
Share-based compensation expense, net of forfeitures	3,691	3,777	11,634	11,952
Common units withheld for employee taxes	(181)	(286)	(4,856)	(4,972)
Purchase of noncontrolling interest				(10,264)
Purchase of capped calls				(19,448)
Ending balance	3,057,538	2,954,507	3,057,538	2,954,507
Federal Realty OP LP | Accumulated Other Comprehensive Income (Loss)
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning balance	2,912	7,042	4,740	4,052
Other comprehensive (loss) income - change in fair value of interest rate swaps, excluding portion attributable to redeemable noncontrolling interests	(680)	(4,870)	(2,508)	(1,880)
Ending balance	2,232	2,172	2,232	2,172
Federal Realty OP LP | Total Partner Capital
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning balance	3,249,029	2,995,618	3,171,594	2,963,509
Net Income (loss), excluding amounts attributable to redeemable noncontrolling Interests	61,649	60,953	281,333	229,671
Other comprehensive (loss) income - change in fair value of interest rate swaps, excluding portion attributable to redeemable noncontrolling interests	(680)	(4,870)	(2,508)	(1,880)
Distributions declared to common unit holders	(97,474)	(93,442)	(287,282)	(275,006)
Distributions on preferred units	(2,008)	(2,008)	(6,024)	(6,024)
Common units issued as a result of common stock issued by Parent Company, net of issuance costs	(86)
Common units issued as a result of common stock issued by Parent Company, net of issuance costs		151,389	54,306	222,319
Common units issued under dividend reinvestment plan	461	476	1,368	1,323
Share-based compensation expense, net of forfeitures	3,691	3,777	11,634	11,952
Common units withheld for employee taxes	(181)	(286)	(4,856)	(4,972)
Purchase of noncontrolling interest				(10,264)
Purchase of capped calls				(19,448)
Ending balance	3,214,558	3,111,467	3,214,558	3,111,467
Federal Realty OP LP | Noncontrolling Interests in Consolidated Partnerships
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning balance	71,071	75,195	72,550	78,650
Net Income (loss), excluding amounts attributable to redeemable noncontrolling Interests	864	766	3,698	1,282
Distributions declared to noncontrolling interests in consolidated partnerships, excluding amounts attributable to redeemable noncontrolling interests	(1,110)	(1,293)	(3,334)	(3,183)
Purchase of noncontrolling interest				(2,094)
Contributions from noncontrolling interests				725
Ending balance	70,587	74,133	70,587	74,133
Federal Realty OP LP | downREIT OP units
Increase (Decrease) in Partners' Capital [Roll Forward]
Conversion and redemption of downREIT OP units	(81)	(675)	(7,334)	(960)
Federal Realty OP LP | downREIT OP units | Common Units
Increase (Decrease) in Partners' Capital [Roll Forward]
Conversion and redemption of downREIT OP units	157	(140)	(5,007)	287
Federal Realty OP LP | downREIT OP units | Total Partner Capital
Increase (Decrease) in Partners' Capital [Roll Forward]
Conversion and redemption of downREIT OP units	157	(140)	(5,007)	287
Federal Realty OP LP | downREIT OP units | Noncontrolling Interests in Consolidated Partnerships
Increase (Decrease) in Partners' Capital [Roll Forward]
Conversion and redemption of downREIT OP units	$ (238)	$ (535)	$ (2,327)	$ (1,247)