DERIVATIVE FINANCIAL INSTRUMENTS (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Notional amount and fair value of the entity's derivative financial instruments
Realized investment gains (losses) - derivatives related to variable annuity contracts, gross	$ (48,192)	$ (10,748)
Realized investment gains (losses) - derivatives related to FIA contracts, gross	3,072
Realized investment gains (losses) - derivatives, gross	(105,350)	7,385
Notional Amount, Other long-term investments	8,213,432		8,412,748
Fair Value, Other long-term investments	277,724		307,567
Notional Amount, Other liabilities	8,798,080		7,594,421
Fair Value, Other liabilities	498,200		457,802
Cash flow hedges | Inflation
Notional amount and fair value of the entity's derivative financial instruments
Notional Amount, Other long-term investments	39,882
Fair Value, Other long-term investments	12
Notional Amount, Other liabilities	143,083		182,965
Fair Value, Other liabilities	199		1,865
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	4,250	(16,484)
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	57,368	(16,556)
Realized investment gains (losses) - derivatives, gross		1,003
Notional Amount, Other long-term investments	245,000		200,000
Fair Value, Other long-term investments	3,104		1,961
Notional Amount, Other liabilities	1,230,000		1,230,000
Fair Value, Other liabilities	99,091		153,322
Positions held	0
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	(1,850)	(10,433)
Notional Amount, Other liabilities	1,000		1,500
Fair Value, Other liabilities	2,959		1,744
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	(60,169)	16,775
Notional Amount, Other long-term investments	44,858		80,376
Fair Value, Other long-term investments	1,011		1,517
Notional Amount, Other liabilities	2,598,197		2,578,590
Fair Value, Other liabilities	266,581		206,918
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	(82,287)	80,375
Notional Amount, Other long-term investments	5,222,067		6,113,017
Fair Value, Other long-term investments	142,797		194,616
Notional Amount, Other liabilities	3,598,490		2,494,142
Fair Value, Other liabilities	68,855		38,388
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	39,834
Fair Value, Other long-term investments	131
Notional Amount, Other liabilities	257,692		322,902
Fair Value, Other liabilities	1,072		5,221
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	1,733
Notional Amount, Other liabilities	395,528		244,424
Fair Value, Other liabilities	35,929		25,324
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	(2,651)	(23,225)
Realized investment gains (losses) - derivatives related to FIA contracts, gross	345
Notional Amount, Other long-term investments	78,458		3,387
Fair Value, Other long-term investments	484		111
Notional Amount, Other liabilities	70,047		164,595
Fair Value, Other liabilities	700		6,595
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 contracts, gross	(1,278)	8,083
Notional Amount, Other long-term investments	40,062		14,338
Fair Value, Other long-term investments	208		321
Notional Amount, Other liabilities	104,052		118,008
Fair Value, Other liabilities	294		840
Derivatives not designated as hedging instruments | Volatility futures
Notional amount and fair value of the entity's derivative financial instruments
Positions held	0
Derivatives not designated as hedging instruments | Interest rate caps
Notional amount and fair value of the entity's derivative financial instruments
Positions held	0
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	(12,341)	(28,406)
Realized investment gains (losses) - derivatives related to FIA contracts, gross	994
Notional Amount, Other long-term investments	1,877,846		1,376,205
Fair Value, Other long-term investments	108,706		78,277
Notional Amount, Other liabilities	399,765		257,065
Fair Value, Other liabilities	22,489		17,558
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	(9,403)	(4,102)
Notional Amount, Other long-term investments	625,000		625,000
Fair Value, Other long-term investments	20,889		30,291
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	(61)	355
Notional Amount, Other long-term investments	425		425
Fair Value, Other long-term investments	382		473
Notional Amount, Other liabilities	226		230
Fair Value, Other liabilities	$ 31		$ 27
Derivatives not designated as hedging instruments | Volatility options
Notional amount and fair value of the entity's derivative financial instruments
Positions held	0