EQUITY SECURITIES (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Debt and Equity Securities, FV-NI [Line Items]
Equity Securities, FV-NI, Gain (Loss)	$ (813,000)	$ (700,000)	$ (3,268,000)	$ (1,818,000)
Equity Securities, FV-NI, Realized Gain (Loss)	0	0	2,161,000	0
Equity Securities, FV-NI, Unrealized Gain (Loss)	(813,000)	(700,000)	(5,429,000)	(1,818,000)
Other Long-term Investments	3,900,000		3,900,000		$ 3,900,000
Equity Securities without Readily Determinable Fair Value, Downward Price Adjustment, Cumulative Amount	6,200,000		6,200,000
Equity Securities without Readily Determinable Fair Value, Upward Price Adjustment, Cumulative Amount	958,000		958,000
Equity Securities without Readily Determinable Fair Value, Impairment Loss And Downward Adjustments	0	$ (2,750,000)	0	$ (5,708,000)
Marketable Securities and Equity Securities, FV-NI	1,800,000		1,800,000		11,100,000
Equity Method Investments	$ 44,600,000		$ 44,600,000		$ 37,300,000