EQUITY (Schedule of Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Accumulated Other Comprehensive Income (Loss), Other than Temporary Impairment, Not Credit Loss, Net of Tax, Debt Securities [Abstract]
Reclassification of realized losses (gains) to the Consolidated Statements of Operations related to bond investments assessed as other-than-temporary-impairment ("OTTI")								$ 100
Reclassification of fair value gains on sold or redeemed bonds into the Consolidated Statements of Operations	$ (1,851)			$ (5,080)			$ (26,115)	(5,080)
Reinstatement of fair value gains related to bond investments due to deconsolidation of consolidated property partnerships	0			0			0	9,415
Net change in AOCI	(673)	$ (21,143)	$ (3,140)	(3,375)	$ 4,047	$ 9,160
Investments in Debt Securities [Member]
Accumulated Other Comprehensive Income (Loss), Other than Temporary Impairment, Not Credit Loss, Net of Tax, Debt Securities [Abstract]
Beginning Balance	13,397		37,625	54,857		44,459	37,625	44,459
Net unrealized gains	961			1,025			997	2,143
Reclassification of realized gains on sold or redeemed bonds into the Consolidated Statements of Operations				(5,080)
Reclassification of realized losses (gains) to the Consolidated Statements of Operations related to bond investments assessed as other-than-temporary-impairment ("OTTI")				141
Reclassification of fair value gains on sold or redeemed bonds into the Consolidated Statements of Operations	(1,851)						(26,115)	(5,080)
Reclassification of credit-related losses to the Consolidated Statements of Operations related to bond investments assessed as OTTI								6
Reinstatement of fair value gains related to bond investments due to deconsolidation of consolidated property partnerships								9,415
Net change in AOCI	(890)			(3,914)			(25,118)	6,484
Ending Balance	12,507	13,397		50,943	54,857		12,507	50,943
Income Tax Expense [Member]
Accumulated Other Comprehensive Income (Loss), Other than Temporary Impairment, Not Credit Loss, Net of Tax, Debt Securities [Abstract]
Beginning Balance				(14)
Income tax expense				14
Net change in AOCI				14
Ending Balance					(14)
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss), Other than Temporary Impairment, Not Credit Loss, Net of Tax, Debt Securities [Abstract]
Beginning Balance	17		72	(483)		(3,306)	72	(3,306)
Net unrealized gains	217			525			162	3,348
Income tax expense								42
Net change in AOCI	217			525			162	3,348
Ending Balance	234	17		42	(483)		234	42
Accumulated Other Comprehensive Income Loss [Member]
Accumulated Other Comprehensive Income (Loss), Other than Temporary Impairment, Not Credit Loss, Net of Tax, Debt Securities [Abstract]
Beginning Balance	13,414		$ 37,697	54,360		$ 41,153	37,697	41,153
Net unrealized gains	1,178			1,550			1,159	5,491
Reclassification of realized gains on sold or redeemed bonds into the Consolidated Statements of Operations				(5,080)
Reclassification of realized losses (gains) to the Consolidated Statements of Operations related to bond investments assessed as other-than-temporary-impairment ("OTTI")				141
Reclassification of fair value gains on sold or redeemed bonds into the Consolidated Statements of Operations	(1,851)						(26,115)	(5,080)
Reclassification of credit-related losses to the Consolidated Statements of Operations related to bond investments assessed as OTTI								6
Reinstatement of fair value gains related to bond investments due to deconsolidation of consolidated property partnerships								9,415
Income tax expense				14
Net change in AOCI	(673)			(3,375)			(24,956)	9,832
Ending Balance	$ 12,741	$ 13,414		$ 50,985	$ 54,360		$ 12,741	$ 50,985