Goodwill and Other Intangible Assets (Components of Goodwill and Other Intangible Assets, Net) (Details) - USD ($) $ in Thousands		3 Months Ended			9 Months Ended
	Aug. 06, 2021	Sep. 30, 2021	Sep. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
Goodwill and Intangible Assets [Roll Forward]
Goodwill, beginning balance				$ 78,008	$ 31,756	$ 78,008
Acquisitions					815	0
Impairment Losses				(46,252)	0	(46,252)
Goodwill, ending balance		$ 32,571	$ 31,756		32,571	31,756
Indefinite-lived Intangible Assets [Roll Forward]
Acquisitions					0	0
Finite-lived Intangible Assets [Roll Forward]
Intangibles with a finite life, net, beginning balance				474	310	474
Acquisitions					6,527	0
Impairment Losses					0	0
Amortization					(218)	(123)
Intangibles with a finite life, net, ending balance		6,619	351		6,619	351
Goodwill and Intangible Assets [Roll Forward]
Goodwill and other intangible assets, net, beginning balance				265,993	207,577	265,993
Acquisitions					7,342	0
Impairments of goodwill and intangible assets		0	0		0	(58,252)
Amortization					(218)	(123)
Goodwill and other intangible assets, net, ending balance		214,701	207,618		214,701	207,618
Goodwill		32,571	31,756		32,571	31,756
REAOH
Goodwill and Intangible Assets [Roll Forward]
Goodwill, ending balance	$ 815	815			815
Goodwill and Intangible Assets [Roll Forward]
Purchase price allocated to non-compete agreement		$ 6,527			6,527
Amortization period	10 years	10 years
Goodwill	$ 815	$ 815			815
Intangible asset associated with benefit under the MSA
Indefinite-lived Intangible Assets [Roll Forward]
Indefinite life intangibles, beginning balance				107,511	107,511	107,511
Impairment Losses					0	0
Indefinite life intangibles, ending balance		107,511	107,511		107,511	107,511
Trademark - Douglas Elliman
Indefinite-lived Intangible Assets [Roll Forward]
Indefinite life intangibles, beginning balance				80,000	68,000	80,000
Impairment Losses				$ (12,000)	0	(12,000)
Indefinite life intangibles, ending balance		$ 68,000	$ 68,000		$ 68,000	$ 68,000