RECLASSIFICATION FROM ACCUMULATED OTHER COMPREHENSIVE INCOME INTO NET INCOME (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Provision (reversal) for credit losses on securities	$ (25,134)	$ 8,859	$ 19,015	$ 16,375
Net income (loss)	44,129	(25,020)	(1,563,126)	130,892
Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net income (loss)	(31,803)	(32,164)	(742,194)	(89,844)
Accumulated Net Investment Gain (Loss) Including Portion Attributable to Noncontrolling Interest | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Gain (loss) on settlement of investments, net	(6,669)	(41,023)	(761,209)	(106,219)
Provision (reversal) for credit losses on securities	$ (25,134)	$ 8,859	$ 19,015	$ 16,375