Earnings Per Share (Schedule Of Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Earnings Per Share Narrative [Line Items]
Net income	$ 395,661	$ 269,081	$ 135,888
Less: Preferred share dividends	(8,034)	(8,042)	(8,042)
Less: Income from operations attributable to noncontrolling interests	(10,170)	(7,583)	(4,182)
Less: Earnings allocated to unvested shares	(1,328)	(1,211)	(992)
Net income available for common shareholders, basic	376,129	252,245	122,672
Add: Income attributable to downREIT operating partnership units	2,810	0	0
Net income available for common shareholders, diluted	$ 378,939	$ 252,245	$ 122,672
Weighted average common shares outstanding—basic	79,854	77,336	75,515
Open forward contracts for share issuances	0	32	0
DownREIT operating partnership units	654	0	0
Weighted average common shares outstanding—diluted	80,508	77,368	75,515
EARNINGS PER COMMON SHARE, BASIC
Net income available for common shareholders	$ 4.71	$ 3.26	$ 1.62
EARNINGS PER COMMON SHARE, DILUTED
Net income available for common shareholders	$ 4.71	$ 3.26	$ 1.62
Federal Realty OP LP
Earnings Per Share Narrative [Line Items]
Net income	$ 395,661	$ 269,081	$ 135,888
Less: Preferred unit distributions	(8,034)	(8,042)	(8,042)
Less: Income from operations attributable to noncontrolling interests	(10,170)	(7,583)	(4,182)
Less: Earnings allocated to unvested units	(1,328)	(1,211)	(992)
Net income available for common unit holders, basic	376,129	252,245	122,672
Add: Income attributable to downREIT operating partnership units	2,810	0	0
Net income available for common unit holders, diluted	$ 378,939	$ 252,245	$ 122,672
Weighted average common units outstanding—basic	79,854	77,336	75,515
Common unit issuances relating to open common share forward contracts	0	32	0
DownREIT operating partnership units	654	0	0
Weighted average common units outstanding—diluted	80,508	77,368	75,515
EARNINGS PER COMMON UNIT, BASIC
Net income available for common unit holders	$ 4.71	$ 3.26	$ 1.62
EARNINGS PER COMMON UNIT, DILUTED
Net income available for common unit holders	$ 4.71	$ 3.26	$ 1.62