Consolidated Statement of Stockholders' Deficiency - USD ($) $ in Thousands	3 Months Ended				12 Months Ended
	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance (in shares)		148,084,900			148,084,900
Beginning Balance		$ (685,016)		$ (547,366)	$ (685,016)	$ (547,366)	$ (331,760)
Net income	$ 32,256	(3,231)	$ 10,667	15,033	92,938	101,015	58,007
Total other comprehensive loss					734	2,871	(1,375)
Total comprehensive income					93,672	103,886	56,632
Distributions and dividends on common stock					(125,128)	(237,339)	(226,283)
Restricted stock grant					0	0	0
Surrender of shares in connection with restricted stock vesting					(2,186)	(2,174)	(3,656)
Surrender of shares in connection with stock option exercise					$ (7,357)	(19,058)
Effect of stock dividend						$ 0	0
Exercise of stock options (in shares)					620,527	1,824,351
Exercise of stock options					$ 6,913	$ 15,817
Issuance of common stock					52,563
Stock-based compensation					9,483	9,469	9,951
Acquisition of Douglas Elliman Realty, LLC							(45,153)
Basis adjustment on non-controlling interest						(6,415)
Distributions to non-controlling interest					(448)	$ (286)	(2,521)
Other					$ 80
Ending Balance (in shares)	148,084,900		148,084,900		148,084,900	148,084,900
Ending Balance	$ (659,687)		$ (685,016)		$ (659,687)	$ (685,016)	(547,366)
Accounting Standards Update [Extensible List]					us-gaap:AccountingStandardsUpdate201817Member	us-gaap:AccountingStandardsUpdate201802Member
Cumulative Effect, Period of Adoption, Adjustment
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance		$ (2,263)		$ (1,550)	$ (2,263)	$ (1,550)	(4,576)
Ending Balance			$ (2,263)			$ (2,263)	$ (1,550)
Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance (in shares)		148,084,900		140,914,642	148,084,900	140,914,642	134,365,424
Beginning Balance		$ 14,808		$ 14,092	$ 14,808	$ 14,092	$ 13,437
Restricted stock grant (in shares)					425,000	60,000	31,666
Restricted stock grant					$ 43	$ 6	$ 3
Surrender of shares in connection with restricted stock vesting (in shares)					(216,542)	(221,668)	(192,119)
Surrender of shares in connection with restricted stock vesting					$ (22)	$ (22)	$ (19)
Surrender of shares in connection with stock option exercise (in shares)					(589,256)	(1,529,512)
Surrender of shares in connection with stock option exercise					$ (59)	$ (153)
Effect of stock dividend (in shares)						7,037,087	6,709,671
Effect of stock dividend						$ 703	$ 671
Exercise of stock options (in shares)					620,527	1,824,351
Exercise of stock options					$ 62	$ 182
Issuance of common stock (in shares)					5,000,000
Issuance of common stock					$ 500
Ending Balance (in shares)	153,324,629		148,084,900		153,324,629	148,084,900	140,914,642
Ending Balance	$ 15,332		$ 14,808		$ 15,332	$ 14,808	$ 14,092
Additional Paid-In Capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance		0		0	0	0	0
Distributions and dividends on common stock					(58,892)	(4,041)	(6,311)
Restricted stock grant					(43)	(6)	(3)
Surrender of shares in connection with restricted stock vesting					(2,164)	(2,152)	(3,637)
Surrender of shares in connection with stock option exercise					(7,298)	(18,905)
Exercise of stock options					6,851	15,635
Issuance of common stock					52,063
Stock-based compensation					9,483	9,469	9,951
Ending Balance	0		0		0	0	0
Accumulated Deficit
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance		(678,464)		(542,169)	(678,464)	(542,169)	(414,785)
Net income					92,938	100,974	58,105
Distributions and dividends on common stock					(66,236)	(233,298)	(219,972)
Effect of stock dividend						(703)	(671)
Acquisition of Douglas Elliman Realty, LLC							28,800
Basis adjustment on non-controlling interest						(6,415)
Other					80
Ending Balance	(653,945)		(678,464)		(653,945)	(678,464)	(542,169)
Accumulated Deficit | Cumulative Effect, Period of Adoption, Adjustment
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance		(2,263)		3,147	(2,263)	3,147	6,354
Ending Balance			(2,263)			(2,263)	3,147
Accumulated Other Comprehensive Income (Loss)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance		(21,808)		(19,982)	(21,808)	(19,982)	(12,571)
Total other comprehensive loss					734	2,871	(1,375)
Ending Balance	(21,074)		(21,808)		(21,074)	(21,808)	(19,982)
Accumulated Other Comprehensive Income (Loss) | Cumulative Effect, Period of Adoption, Adjustment
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance				(4,697)		(4,697)	(6,036)
Ending Balance							(4,697)
Non-controlling Interest
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance		$ 448		$ 693	448	693	82,159
Net income						41	(98)
Acquisition of Douglas Elliman Realty, LLC							(73,953)
Distributions to non-controlling interest					(448)	(286)	(2,521)
Ending Balance	$ 0		$ 448		$ 0	$ 448	693
Non-controlling Interest | Cumulative Effect, Period of Adoption, Adjustment
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance							$ (4,894)