ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Reclassifications out of accumulated other comprehensive income (loss)
Benefits and settlement expenses, net of reinsurance ceded	$ (728,519)	$ (581,880)
Realized investment gains (losses): All other investments	72,114	(4,145)
Net impairment losses recognized in earnings	(1,591)	(4,584)
Income before income tax	125,205	117,627
Tax benefit (expense)	(41,566)	(39,336)
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	(670)	(497)
Income before income tax	(670)	(497)
Tax benefit (expense)	234	174
Net income	(436)	(323)
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	7,370	12,310
Net impairment losses recognized in earnings	(1,591)	(4,584)
Income before income tax	5,779	7,726
Tax benefit (expense)	(2,023)	(2,704)
Net income	$ 3,756	$ 5,022