DERIVATIVE FINANCIAL INSTRUMENTS (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Notional amount and fair value of the entity's derivative financial instruments
Realized investment gains (losses) - derivatives, gross	$ (13,492)	$ 82,161	$ (227,816)
Notional Amount, Other long-term investments	7,174,182	5,685,338
Fair Value, Other long-term investments	270,701	210,320
Notional Amount, Other liabilities	7,661,143	6,196,027
Fair Value, Other liabilities	629,535	455,161
Derivatives not designated as hedging instruments
Notional amount and fair value of the entity's derivative financial instruments
Realized investment gains (losses) - derivatives related to variable annuity contracts, gross	94,002	(112,006)	(102,832)
Realized investment gains (losses) - derivatives related to FIA contracts, gross	(6,136)	1,092
Realized investment gains (losses) - derivatives, gross	(13,492)	82,161	(227,816)
Derivatives not designated as hedging instruments | PLC
Notional amount and fair value of the entity's derivative financial instruments
Notional Amount, Other long-term investments	1,497,010	1,464,164
Fair Value, Other long-term investments	6,077	1,993
Derivatives not designated as hedging instruments | IUL
Notional amount and fair value of the entity's derivative financial instruments
Realized investment gains (losses) - derivatives, gross	157
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 contracts, gross	27,801	(31,216)	21,138
Notional Amount, Other long-term investments	27,977
Fair Value, Other long-term investments	938
Notional Amount, Other liabilities		322,902
Fair Value, Other liabilities		5,221
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 contracts, gross	(26,104)	(52,640)	(50,797)
Realized investment gains (losses) - derivatives related to FIA contracts, gross	870	173
Notional Amount, Other long-term investments	26,483	3,387
Fair Value, Other long-term investments	427	111
Notional Amount, Other liabilities	385,256	164,595
Fair Value, Other liabilities	15,069	6,595
Derivatives not designated as hedging instruments | Equity futures | IUL
Notional amount and fair value of the entity's derivative financial instruments
Realized investment gains (losses) - derivatives, gross	15
Derivatives not designated as hedging instruments | Currency futures
Notional amount and fair value of the entity's derivative financial instruments
Realized investment gains (losses) - derivatives related to variable annuity contracts, gross	14,433	(469)	(2,763)
Notional Amount, Other long-term investments	197,648	14,338
Fair Value, Other long-term investments	2,384	321
Notional Amount, Other liabilities		118,008
Fair Value, Other liabilities		840
Derivatives not designated as hedging instruments | Volatility futures
Notional amount and fair value of the entity's derivative financial instruments
Positions held	0
Realized investment gains (losses) - derivatives related to variable annuity contracts, gross			(132)
Realized investment gains (losses) - derivatives related to FIA contracts, gross	20	(5)
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 contracts, gross	(744)	(11,310)	(11,792)
Notional Amount, Other liabilities		1,500
Fair Value, Other liabilities		1,744
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 contracts, gross	(41,216)	(95,022)	(37,370)
Realized investment gains (losses) - derivatives related to FIA contracts, gross	9,906	1,866
Notional Amount, Other long-term investments	1,921,167	1,376,205
Fair Value, Other long-term investments	163,212	78,277
Notional Amount, Other liabilities	699,295	257,065
Fair Value, Other liabilities	47,077	17,558
Derivatives not designated as hedging instruments | Equity options | IUL
Notional amount and fair value of the entity's derivative financial instruments
Realized investment gains (losses) - derivatives, gross	150
Derivatives not designated as hedging instruments | Volatility options
Notional amount and fair value of the entity's derivative financial instruments
Realized investment gains (losses) - derivatives related to variable annuity contracts, gross		(115)
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 contracts, gross	(22,280)	1,575	(2,260)
Notional Amount, Other long-term investments	625,000	625,000
Fair Value, Other long-term investments	8,012	30,291
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 contracts, gross	214,164	(157,408)	3,264
Realized investment gains (losses) - derivatives, gross		2,985	(87)
Notional Amount, Other long-term investments	1,550,000	200,000
Fair Value, Other long-term investments	50,743	1,961
Notional Amount, Other liabilities	275,000	1,230,000
Fair Value, Other liabilities	3,599	153,322
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 contracts, gross	(119,844)	162,737	(22,120)
Notional Amount, Other long-term investments	1,302,895	1,921,443
Fair Value, Other long-term investments	37,497	95,376
Notional Amount, Other liabilities	1,702,899	104,180
Fair Value, Other liabilities	63,460	1,496
Derivatives not designated as hedging instruments | Funds withheld derivative
Notional amount and fair value of the entity's derivative financial instruments
Realized investment gains (losses) - derivatives related to variable annuity contracts, gross	47,792	71,862
Notional Amount, Other liabilities	1,233,424	991,568
Fair Value, Other liabilities	57,305	34,251
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	(105,276)	205,176	(132,816)
Notional Amount, Other long-term investments	25,760	80,376
Fair Value, Other long-term investments	1,051	1,517
Notional Amount, Other liabilities	2,562,848	2,578,590
Fair Value, Other liabilities	311,727	206,918
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 related to FIA contracts, gross	(16,932)	(942)
Notional Amount, Other liabilities	749,933	244,424
Fair Value, Other liabilities	124,465	25,324
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			(2,666)
Derivatives not designated as hedging instruments | Derivatives with PLC
Notional amount and fair value of the entity's derivative financial instruments
Realized investment gains (losses) - derivatives, gross	4,085	(15,072)	10,664
Derivatives not designated as hedging instruments | Other derivatives
Notional amount and fair value of the entity's derivative financial instruments
Realized investment gains (losses) - derivatives, gross	(324)	(14)	(79)
Notional Amount, Other long-term investments	242	425
Fair Value, Other long-term investments	360	473
Notional Amount, Other liabilities		230
Fair Value, Other liabilities		27
Derivatives not designated as hedging instruments | Embedded derivative - IUL
Notional amount and fair value of the entity's derivative financial instruments
Realized investment gains (losses) - derivatives, gross	(8)
Notional Amount, Other long-term investments	12,019
Fair Value, Other long-term investments	6,691
Cash flow hedges. | Inflation
Notional amount and fair value of the entity's derivative financial instruments
Notional Amount, Other liabilities	40,469	182,965
Fair Value, Other liabilities	$ 142	$ 1,865