Notes Payable, Long-Term Debt and Other Obligations (Senior Notes, Revolving Credit Facility, and Other) (Details) - USD ($) $ in Thousands	1 Months Ended	9 Months Ended		12 Months Ended
	Apr. 30, 2020	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Purchase price, cash paid		$ 0	$ 323
Senior Notes | 10.5% Senior Notes due 2026, net of unamortized discount of $3,132 and $3,392
Debt Instrument [Line Items]
Interest rate		10.50%
Variable Interest Senior Convertible Debt | 10.5% Senior Notes due 2026, net of unamortized discount of $3,132 and $3,392
Debt Instrument [Line Items]
Interest rate		10.50%
Variable Interest Senior Convertible Debt | 5.5% Variable Interest Senior Convertible Debentures due 2020
Debt Instrument [Line Items]
Interest rate		5.50%
Face amount of debt paid	$ 169,610
Other Notes Payable | Douglas Elliman notes payable to sellers
Debt Instrument [Line Items]
Debt issued		$ 26,300
Principal repaid in year to date		3,750
Due to be repaid in the remainder of 2020		1,250
Due to be repaid in 2021		12,500
Due to be repaid in 2022		12,500
Liggett | Revolving credit facility
Debt Instrument [Line Items]
Amount outstanding		0
Current borrowing capacity		$ 58,800
Douglas Elliman
Debt Instrument [Line Items]
Voting interest acquired				29.41%
Purchase price				$ 40,000
Purchase price, cash paid				10,000
Purchase price, notes payable to sellers				$ 30,000