Consolidated Statement of Stockholders' Deficiency - USD ($) $ in Thousands	3 Months Ended				12 Months Ended
	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance (in shares)		140,914,642			140,914,642
Beginning Balance		$ (547,366)		$ (331,760)	$ (547,366)	$ (331,760)	$ (253,272)
Impact of adoption of new accounting standards					(1,550)	(4,576)
Net income	$ 10,667	$ 15,033	$ 20,319	$ 3,664	101,015	58,007	90,750
Total other comprehensive loss					2,871	(1,375)	(1,326)
Distributions and dividends on common stock					(237,339)	(226,283)	(215,182)
Restricted stock grant					0	0
Surrender of shares in connection with restricted stock vesting					(2,174)	(3,656)	(4,100)
Surrender of shares in connection with stock option exercise					(19,058)
Effect of stock dividend					$ 0	$ 0	0
Cancellation of shares under share lending agreement							$ 0
Exercise of stock options (in shares)					1,824,351	0	0
Exercise of stock options					$ 15,817
Issuance of common stock							$ 43,230
Stock-based compensation					9,469	$ 9,951	10,887
Acquisition of Douglas Elliman Realty, LLC						(45,153)
Basis adjustment on non-controlling interest					(6,415)
Distributions to non-controlling interest					$ (286)	$ (2,521)	(2,747)
Ending Balance (in shares)	148,084,900		140,914,642		148,084,900	140,914,642
Ending Balance	$ (685,016)		$ (547,366)		$ (685,016)	$ (547,366)	$ (331,760)
Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance (in shares)		140,914,642		134,365,424	140,914,642	134,365,424	127,739,481
Beginning Balance		$ 14,092		$ 13,437	$ 14,092	$ 13,437	$ 12,774
Restricted stock grant (in shares)					60,000	31,666
Restricted stock grant					$ 6	$ 3
Surrender of shares in connection with restricted stock vesting (in shares)					(221,668)	(192,119)	(191,967)
Surrender of shares in connection with restricted stock vesting					$ (22)	$ (19)	$ (19)
Surrender of shares in connection with stock option exercise (in shares)					(1,529,512)
Surrender of shares in connection with stock option exercise					$ (153)
Effect of stock dividend (in shares)					7,037,087	6,709,671	6,436,512
Effect of stock dividend					$ 703	$ 671	$ 644
Cancellation of shares under share lending agreement (in shares)							(1,618,602)
Cancellation of shares under share lending agreement							$ (162)
Exercise of stock options (in shares)					1,824,351
Exercise of stock options					$ 182
Issuance of common stock (in shares)							2,000,000
Issuance of common stock							$ 200
Ending Balance (in shares)	148,084,900		140,914,642		148,084,900	140,914,642	134,365,424
Ending Balance	$ 14,808		$ 14,092		$ 14,808	$ 14,092	$ 13,437
Additional Paid-in Capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance		0		0	0	0	0
Distributions and dividends on common stock					(4,041)	(6,311)	(49,998)
Restricted stock grant					(6)	(3)
Surrender of shares in connection with restricted stock vesting					(2,152)	(3,637)	(4,081)
Surrender of shares in connection with stock option exercise					(18,905)
Cancellation of shares under share lending agreement							162
Exercise of stock options					15,635
Issuance of common stock							43,030
Stock-based compensation					9,469	9,951	10,887
Ending Balance	0		0		0	0	0
Accumulated Deficit
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance		(542,169)		(414,785)	(542,169)	(414,785)	(333,529)
Impact of adoption of new accounting standards					3,147	6,354
Net income					100,974	58,105	84,572
Distributions and dividends on common stock					(233,298)	(219,972)	(165,184)
Effect of stock dividend					(703)	(671)	(644)
Acquisition of Douglas Elliman Realty, LLC						28,800
Basis adjustment on non-controlling interest					(6,415)
Ending Balance	(678,464)		(542,169)		(678,464)	(542,169)	(414,785)
Accumulated Other Comprehensive Income
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance		(19,982)		(12,571)	(19,982)	(12,571)	(11,245)
Impact of adoption of new accounting standards					(4,697)	(6,036)
Total other comprehensive loss					2,871	(1,375)	(1,326)
Ending Balance	(21,808)		(19,982)		(21,808)	(19,982)	(12,571)
Non-controlling Interest
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance		$ 693		$ 82,159	693	82,159	78,728
Impact of adoption of new accounting standards						(4,894)
Net income					41	(98)	6,178
Acquisition of Douglas Elliman Realty, LLC						(73,953)
Distributions to non-controlling interest					(286)	(2,521)	(2,747)
Ending Balance	$ 448		$ 693		$ 448	$ 693	$ 82,159