Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2025	Dec. 31, 2024
Operating real estate, consolidated variable interest entities	$ 1,827,346	$ 1,827,346	$ 1,825,656
Construction-in-progress, consolidated variable interest entities	25,395	25,395	9,939
Accumulated depreciation and amortization, consolidated variable interest entities	456,303	456,303	424,044
Mortgages payable, consolidated variable interest entities	$ 183,493	$ 183,493	$ 186,643
Preferred shares, authorized	15,000,000	15,000,000	15,000,000
Preferred shares, par value	$ 0.01	$ 0.01	$ 0.01
Common shares of beneficial interest, par value	$ 0.01	$ 0.01	$ 0.01
Common shares of beneficial interest, shares authorized	200,000,000	200,000,000	200,000,000
Common shares of beneficial interest, shares issued	86,265,563	86,265,563	85,666,220
Common shares of beneficial interest, shares outstanding	86,265,563	86,265,563	85,666,220
Federal Realty OP LP
Operating real estate, consolidated variable interest entities	$ 1,827,346	$ 1,827,346	$ 1,825,656
Construction-in-progress, consolidated variable interest entities	25,395	25,395	9,939
Accumulated depreciation and amortization, consolidated variable interest entities	456,303	456,303	424,044
Mortgages payable, consolidated variable interest entities	$ 183,493	$ 183,493	$ 186,643
Preferred units, issued	398,878	398,878	398,878
Preferred units, outstanding	398,878	398,878	398,878
Common units, issued	86,265,563	86,265,563	85,666,220
Common units, outstanding	86,265,563	86,265,563	85,666,220
5.417% Series 1 Cumulative Convertible Preferred Shares, (stated at liquidation preference $25 per share), 392,878 shares issued and outstanding
Preferred shares, percentage	5.417%	5.417%	5.417%
Preferred shares, liquidation preference per share	$ 25	$ 25	$ 25
Preferred shares, shares issued	392,878	392,878	392,878
Preferred shares, shares outstanding	392,878	392,878	392,878
5.0% Series C Cumulative Redeemable Preferred Shares, (stated at liquidation preference $25,000 per share), 6,000 shares issued and outstanding
Preferred shares, percentage		5.00%	5.00%
Preferred shares, liquidation preference per share	$ 25,000	$ 25,000	$ 25,000
Preferred shares, shares issued	6,000	6,000	6,000
Preferred shares, shares outstanding	6,000	6,000	6,000