OTHER COMPREHENSIVE INCOME (LOSS) (Reclassifications Out of AOCI Into Net Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Reclassification out of accumulated comprehensive income into net income available to common shareholders [Line Items]
Other realized gains (losses)	$ 73,143	$ 39,394	$ 102,697	$ (2,272)
Impairment losses	0	(112)	0	(1,302)
Income (loss) before income taxes and interest in income (loss) of equity method investments	253,539	123,831	388,451	(35,282)
Income tax (expense) benefit	(27,865)	(10,893)	(48,641)	(6,026)
Net income (loss) available (attributable) to common shareholders	227,910	112,477	343,645	(72,908)
Unrealized gains (losses) on available for sale investments | Reclassification out of Accumulated Other Comprehensive Income
Reclassification out of accumulated comprehensive income into net income available to common shareholders [Line Items]
Other realized gains (losses)	46,704	9,722	77,579	6,786
Impairment losses	0	(112)	0	(1,302)
Income (loss) before income taxes and interest in income (loss) of equity method investments	46,704	9,610	77,579	5,484
Income tax (expense) benefit	(3,984)	(2,794)	(5,978)	(4,325)
Net income (loss) available (attributable) to common shareholders	$ 42,720	$ 6,816	$ 71,601	$ 1,159