OTHER COMPREHENSIVE INCOME (LOSS) (DETAILS 2) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Reclassification out of accumulated comprehensive income into net income available to common shareholders [Line Items]
Other realized investment gains (losses)									$ (34,315)	$ (65,771)	$ 163,335
OTTI losses									(26,210)	(72,720)	(31,227)
Income before income taxes and interest in income (loss) of equity method investments									521,802	644,659	830,472
Income tax (expense) benefit									(6,340)	(3,028)	(25,908)
Net income available to common shareholders	$ 130,912	$ 176,644	$ 119,491	$ 38,417	$ 134,787	$ 247,620	$ 63,349	$ 155,803	465,462	601,562	770,657
Unrealized gains (losses) on available for sale investments [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification out of accumulated comprehensive income into net income available to common shareholders [Line Items]
Other realized investment gains (losses)									(34,213)	(73,046)	172,399
OTTI losses									(26,210)	(72,720)	(31,227)
Income before income taxes and interest in income (loss) of equity method investments									(60,423)	(145,766)	141,172
Income tax (expense) benefit									(1,767)	775	(26,702)
Net income available to common shareholders									$ (62,190)	$ (144,991)	$ 114,470