FAIR VALUE OF FINANCIAL INSTRUMENTS (Details 3) (Level 3, USD $)	3 Months Ended	12 Months Ended
	Mar. 31, 2014	Dec. 31, 2013
Unobservable Input
Financial instruments that are valued using broker quotes	$ 258,500,000	$ 216,000,000
Financial instruments with book value approximating to fair value	86,700,000	73,900,000
Other asset-backed securities
Unobservable Input
Financial instruments that are valued using broker quotes	194,700,000	195,000,000
Equity securities
Unobservable Input
Financial instruments that are valued using broker quotes	9,800,000
Financial instruments with book value approximating to fair value	67,800,000	68,000,000
Fixed maturities
Unobservable Input
Financial instruments with book value approximating to fair value	3,700,000	3,700,000
Embedded derivatives - GMWB | Actuarial cash flow model | High end of range
Unobservable Input
Nonperformance risk (as a percent)		1.06%
Annuity account balances
Valuation of Level 3 Financial Instruments
Fair Value of Liabilities	105,593,000	107,000,000
Annuity account balances | Actuarial cash flow model | Low end of range
Unobservable Input
Mortality (as a percent)	49.00%	49.00%
Lapse (as a percent)	2.20%	2.20%
Nonperformance risk (as a percent)	0.12%	0.15%
Expenses per policy	88,000	88,000
Return on assets (as a percent)	1.50%	1.50%
Annuity account balances | Actuarial cash flow model | High end of range
Unobservable Input
Mortality (as a percent)	80.00%	80.00%
Lapse (as a percent)	33.00%	33.00%
Nonperformance risk (as a percent)	1.00%
Expenses per policy	102,000	102,000
Return on assets (as a percent)	1.85%	1.85%
Annuity account balances | Actuarial cash flow model | Weighted Average
Unobservable Input
Asset earned rate (as a percent)	5.37%	5.37%
Withdrawal rate (as a percent)	2.20%	2.20%
Embedded derivative - FIA
Valuation of Level 3 Financial Instruments
Fair Value of Liabilities	35,894,000	25,324,000
Embedded derivative - FIA | Actuarial cash flow model | Low end of range
Unobservable Input
Mortality (as a percent)	49.00%	49.00%
Lapse (as a percent)	2.50%	2.50%
Nonperformance risk (as a percent)	0.12%	0.15%
Expenses per policy	83,000	83,000
Withdrawal rate (as a percent)	1.10%	1.10%
Embedded derivative - FIA | Actuarial cash flow model | High end of range
Unobservable Input
Mortality (as a percent)	80.00%	80.00%
Lapse (as a percent)	40.00%	40.00%
Nonperformance risk (as a percent)	1.00%	1.06%
Expenses per policy	97,000	97,000
Withdrawal rate (as a percent)	4.50%	4.50%
Other asset-backed securities
Valuation of Level 3 Financial Instruments
Fair Value of Assets	548,805,000	545,808,000
Other asset-backed securities | Discounted cash flow | Low end of range
Unobservable Input
Liquidity premium (as a percent)	1.00%	1.00%
Paydown rate (as a percent)	8.57%	8.57%
Other asset-backed securities | Discounted cash flow | High end of range
Unobservable Input
Liquidity premium (as a percent)	1.57%	1.68%
Paydown rate (as a percent)	17.42%	16.87%
Other asset-backed securities | Discounted cash flow | Weighted Average
Unobservable Input
Liquidity premium (as a percent)	1.13%	1.08%
Paydown rate (as a percent)	12.37%	12.05%
Corporate bonds
Valuation of Level 3 Financial Instruments
Fair Value of Assets	1,535,409,000	1,555,898,000
Unobservable Input
Financial instruments that are valued using broker quotes	54,000,000	21,000,000
Financial instruments with book value approximating to fair value	15,200,000	2,200,000
Corporate bonds | Discounted cash flow | Low end of range
Unobservable Input
Spread over treasury (as a percent)	0.70%	0.11%
Corporate bonds | Discounted cash flow | High end of range
Unobservable Input
Spread over treasury (as a percent)	6.75%	6.75%
Corporate bonds | Discounted cash flow | Weighted Average
Unobservable Input
Spread over treasury (as a percent)	2.10%	2.06%
Embedded derivatives - GMWB
Valuation of Level 3 Financial Instruments
Fair Value of Assets	$ 66,607,000	$ 93,881,000
Embedded derivatives - GMWB | Actuarial cash flow model | Low end of range
Unobservable Input
Mortality (as a percent)	49.00%	49.00%
Lapse (as a percent)	0.00%	0.00%
Utilization (as a percent)	97.00%	97.00%
Nonperformance risk (as a percent)	0.12%	0.15%
Embedded derivatives - GMWB | Actuarial cash flow model | High end of range
Unobservable Input
Mortality (as a percent)	80.00%	80.00%
Lapse (as a percent)	24.00%	24.00%
Utilization (as a percent)	103.00%	103.00%
Nonperformance risk (as a percent)	1.00%	1.06%