DERIVATIVE FINANCIAL INSTRUMENTS (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Notional amount and fair value of the entity's derivative financial instruments
Realized investment gains (losses) - derivatives related to variable annuity and FIA contracts, gross	$ 11,247,000	$ (32,534,000)	$ (1,988,000)	$ (69,106,000)
Realized investment gains (losses) - derivatives, gross	41,326,000	(134,222,000)	192,592,000	(212,399,000)
Notional Amount, Other long-term investments	7,698,273,000		7,698,273,000		6,163,061,000
Fair Value, Other long-term investments	266,730,000		266,730,000		113,364,000
Notional Amount, Other liabilities	8,044,807,000		8,044,807,000		9,672,554,000
Fair Value, Other liabilities	434,232,000		434,232,000		657,874,000
Cash posted as collateral	81,000,000		81,000,000
Securities posted as collateral	52,200,000		52,200,000
Cash collateral received	6,000,000		6,000,000		11,280,000
Cash flow hedges. | Inflation
Notional amount and fair value of the entity's derivative financial instruments
Notional Amount, Other liabilities	182,965,000		182,965,000		182,965,000
Fair Value, Other liabilities	3,806,000		3,806,000		5,027,000
Derivatives not designated as hedging instruments | Interest rate futures
Notional amount and fair value of the entity's derivative financial instruments
Realized investment gains (losses) - derivatives related to variable annuity and FIA contracts, gross	(2,255,000)	(3,371,000)	(26,393,000)	32,419,000
Notional Amount, Other liabilities	175,681,000		175,681,000		893,476,000
Fair Value, Other liabilities	531,000		531,000		13,970,000
Derivatives not designated as hedging instruments | Interest rate swaps
Notional amount and fair value of the entity's derivative financial instruments
Realized investment gains (losses) - derivatives related to variable annuity and FIA contracts, gross	(19,224,000)	6,361,000	(125,502,000)	10,187,000
Realized investment gains (losses) - derivatives, gross	72,000	199,000	2,984,000	(680,000)
Notional Amount, Other long-term investments	200,000,000		200,000,000		355,000,000
Fair Value, Other long-term investments	2,035,000		2,035,000		6,532,000
Notional Amount, Other liabilities	1,500,000,000		1,500,000,000		400,000,000
Fair Value, Other liabilities	132,592,000		132,592,000		10,025,000
Derivatives not designated as hedging instruments | Variance swaps
Notional amount and fair value of the entity's derivative financial instruments
Realized investment gains (losses) - derivatives related to variable annuity and FIA contracts, gross	(1,347,000)	(5,840,000)	(9,566,000)	(6,660,000)
Notional Amount, Other long-term investments					500,000
Fair Value, Other long-term investments					406,000
Notional Amount, Other liabilities					2,675,000
Fair Value, Other liabilities					12,198,000
Derivatives not designated as hedging instruments | Embedded derivative - Modco reinsurance treaties
Notional amount and fair value of the entity's derivative financial instruments
Realized investment gains (losses) - derivatives, gross	30,074,000	(101,999,000)	191,847,000	(139,972,000)
Notional Amount, Other long-term investments	45,314,000		45,314,000		30,244,000
Fair Value, Other long-term investments	802,000		802,000		1,330,000
Notional Amount, Other liabilities	2,598,832,000		2,598,832,000		2,655,134,000
Fair Value, Other liabilities	219,532,000		219,532,000		411,907,000
Derivatives not designated as hedging instruments | Embedded derivative - FIA
Notional amount and fair value of the entity's derivative financial instruments
Realized investment gains (losses) - derivatives, gross	(104,000)		(145,000)
Notional Amount, Other liabilities	104,951,000		104,951,000
Fair Value, Other liabilities	9,199,000		9,199,000
Derivatives not designated as hedging instruments | Embedded derivative - GMWB
Notional amount and fair value of the entity's derivative financial instruments
Realized investment gains (losses) - derivatives related to variable annuity and FIA contracts, gross	80,541,000	2,921,000	264,231,000	(32,369,000)
Notional Amount, Other long-term investments	5,200,449,000		5,200,449,000		1,640,075,000
Fair Value, Other long-term investments	152,761,000		152,761,000		30,261,000
Notional Amount, Other liabilities	3,117,089,000		3,117,089,000		5,253,961,000
Fair Value, Other liabilities	57,799,000		57,799,000		199,530,000
Derivatives not designated as hedging instruments | Interest rate futures
Notional amount and fair value of the entity's derivative financial instruments
Notional Amount, Other long-term investments	111,534,000		111,534,000
Fair Value, Other long-term investments	1,106,000		1,106,000
Derivatives not designated as hedging instruments | Equity futures
Notional amount and fair value of the entity's derivative financial instruments
Realized investment gains (losses) - derivatives related to variable annuity and FIA contracts, gross	(12,568,000)	(17,324,000)	(39,829,000)	(42,643,000)
Notional Amount, Other long-term investments	47,994,000		47,994,000		147,581,000
Fair Value, Other long-term investments	937,000		937,000		595,000
Notional Amount, Other liabilities	94,457,000		94,457,000		152,364,000
Fair Value, Other liabilities	1,484,000		1,484,000		3,316,000
Derivatives not designated as hedging instruments | Currency future
Notional amount and fair value of the entity's derivative financial instruments
Realized investment gains (losses) - derivatives related to variable annuity and FIA contracts, gross	(6,531,000)	(3,078,000)	1,440,000	(2,298,000)
Notional Amount, Other long-term investments					15,944,000
Fair Value, Other long-term investments					784,000
Notional Amount, Other liabilities	126,389,000		126,389,000		131,979,000
Fair Value, Other liabilities	3,350,000		3,350,000		1,901,000
Derivatives not designated as hedging instruments | Volatility futures
Notional amount and fair value of the entity's derivative financial instruments
Realized investment gains (losses) - derivatives related to variable annuity and FIA contracts, gross				(132,000)
Positions held	0		0
Derivatives not designated as hedging instruments | Interest rate caps
Notional amount and fair value of the entity's derivative financial instruments
Realized investment gains (losses) - derivatives, gross		(143,000)		(2,658,000)
Notional Amount, Other long-term investments					3,000,000,000
Derivatives not designated as hedging instruments | Equity options
Notional amount and fair value of the entity's derivative financial instruments
Realized investment gains (losses) - derivatives related to variable annuity and FIA contracts, gross	(29,094,000)	(9,184,000)	(65,631,000)	(29,903,000)
Notional Amount, Other long-term investments	1,467,720,000		1,467,720,000		573,493,000
Fair Value, Other long-term investments	80,754,000		80,754,000		61,833,000
Notional Amount, Other liabilities	144,408,000		144,408,000
Fair Value, Other liabilities	5,939,000		5,939,000
Derivatives not designated as hedging instruments | Interest rate swaptions
Notional amount and fair value of the entity's derivative financial instruments
Realized investment gains (losses) - derivatives related to variable annuity and FIA contracts, gross	1,725,000	(3,019,000)	(738,000)	2,293,000
Notional Amount, Other long-term investments	625,000,000		625,000,000		400,000,000
Fair Value, Other long-term investments	27,978,000		27,978,000		11,370,000
Derivatives not designated as hedging instruments | Other.
Notional amount and fair value of the entity's derivative financial instruments
Realized investment gains (losses) - derivatives, gross	37,000	255,000	(106,000)	17,000
Notional Amount, Other long-term investments	262,000		262,000		224,000
Fair Value, Other long-term investments	357,000		357,000		253,000
Derivatives not designated as hedging instruments | Other - FIA volatility futures
Notional amount and fair value of the entity's derivative financial instruments
Notional Amount, Other liabilities	$ 35,000		$ 35,000