ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Reclassifications Out of Accumulated Other Comprehensive Income (Loss)
Benefits and settlement expenses, net of reinsurance ceded	$ (622,910)	$ (627,993)	$ (1,759,780)	$ (1,780,416)
Realized investment gains (losses): All other investments	(19,268)	122,476	(133,741)	225,838
Net impairment losses recognized in earnings	(8,681)	(8,499)	(17,265)	(40,537)
Income before income tax	113,355	106,689	302,096	364,822
Tax (expense) or benefit	(37,107)	(35,778)	(98,966)	(116,428)
Gains and losses on derivative instruments | Amount Reclassified from Accumulated Other Comprehensive Income (Loss)
Reclassifications Out of Accumulated Other Comprehensive Income (Loss)
Benefits and settlement expenses, net of reinsurance ceded	(572)		(1,649)
Income before income tax	(572)		(1,649)
Tax (expense) or benefit	200		577
Net of tax	(372)		(1,072)
Unrealized gains and losses on available-for-sale securities | Amount Reclassified from Accumulated Other Comprehensive Income (Loss)
Reclassifications Out of Accumulated Other Comprehensive Income (Loss)
Realized investment gains (losses): All other investments	10,546		44,503
Net impairment losses recognized in earnings	(8,681)		(17,265)
Income before income tax	1,865		27,238
Tax (expense) or benefit	(653)		(9,533)
Net of tax	$ 1,212		$ 17,705