Earnings Per Share (Schedule Of Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Net income	$ 158,774	$ 54,541	$ 277,969	$ 152,339
Less: Preferred share dividends	(2,008)	(2,010)	(6,026)	(6,031)
Less: Income from operations attributable to noncontrolling interests	(2,636)	(2,419)	(8,171)	(5,777)
Less: Earnings allocated to unvested shares	(535)	(309)	(935)	(901)
Net income available for common shareholders, basic and diluted	$ 153,595	$ 49,803	$ 262,837	$ 139,630
Weighted average common shares outstanding, basic	80,765	77,485	79,480	77,269
Open forward contracts for share issuances	0	90	1	18
DownREIT operating partnership units	652	0	656	0
Weighted average common shares outstanding, diluted	81,511	77,575	80,137	77,287
EARNINGS PER COMMON SHARE, BASIC:
Net income available for common shareholders	$ 1.90	$ 0.64	$ 3.31	$ 1.81
EARNINGS PER COMMON SHARE, DILUTED:
Net income available for common shareholders	$ 1.89	$ 0.64	$ 3.31	$ 1.81
5.417% Series 1 Cumulative Convertible Preferred Shares
5.417% Series 1 Cumulative Convertible Preferred Shares	94	0	0	0
Federal Realty OP LP
Net income	$ 158,774	$ 54,541	$ 277,969	$ 152,339
Less: Preferred unit distributions	(2,008)	(2,010)	(6,026)	(6,031)
Less: Income from operations attributable to noncontrolling interests	(2,636)	(2,419)	(8,171)	(5,777)
Less: Earnings allocated to unvested units	(535)	(309)	(935)	(901)
Net income available to common unit holders, basic and diluted	$ 153,595	$ 49,803	$ 262,837	$ 139,630
Weighted average common units outstanding, basic	80,765	77,485	79,480	77,269
Common unit issuances relating to open common share forward contracts	0	90	1	18
DownREIT operating partnership units	652	0	656	0
Weighted average common units outstanding, diluted	81,511	77,575	80,137	77,287
EARNINGS PER COMMON UNIT, BASIC:
Net income available for common shareholders	$ 1.90	$ 0.64	$ 3.31	$ 1.81
EARNINGS PER COMMON UNIT, DILUTED:
Net income available for common unit holders	$ 1.89	$ 0.64	$ 3.31	$ 1.81
Federal Realty OP LP | 5.417% Series 1 Cumulative Convertible Preferred Units
5.417% Series 1 Cumulative Convertible Preferred Units	94	0	0	0