Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2023	Dec. 31, 2022
Operating real estate, consolidated variable interest entities	$ 2,013,166	$ 2,013,166	$ 1,997,583
Construction-in-progress, consolidated variable interest entities	11,030	11,030	8,477
Accumulated depreciation and amortization, consolidated variable interest entities	402,929	402,929	362,921
Mortgages payable, consolidated variable interest entities	$ 189,928	$ 189,928	$ 191,827
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	100,000,000
Common shares of beneficial interest, shares issued	81,618,162	81,618,162	81,342,959
Common shares of beneficial interest, shares outstanding	81,618,162	81,618,162	81,342,959
Federal Realty OP LP
Operating real estate, consolidated variable interest entities	$ 2,013,166	$ 2,013,166	$ 1,997,583
Construction-in-progress, consolidated variable interest entities	11,030	11,030	8,477
Accumulated depreciation and amortization, consolidated variable interest entities	402,929	402,929	362,921
Mortgages payable, consolidated variable interest entities	$ 189,928	$ 189,928	$ 191,827
Preferred units, issued	398,878	398,878	398,878
Preferred units, outstanding	398,878	398,878	398,878
Common units, issued	81,618,162	81,618,162	81,342,959
Common units, outstanding	81,618,162	81,618,162	81,342,959
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
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