INVESTMENTS - AVAILABLE FOR SALE SECURITIES (DETAILS) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2013		Dec. 31, 2012
Schedule of Available-for-sale Securities [Line Items]
Trading securities	$ 241.0		$ 266.2
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Net unrealized appreciation (depreciation) on fixed maturity securities, available for sale, on which an other-than-temporary impairment loss has been recognized	7.5		9.8
Net unrealized gains (losses) on all other investments	1,602.1		2,986.5
Adjustment to present value of future profits (a)	(176.5)	[1]	(193.0)	[1]
Adjustment to deferred acquisition costs	(320.1)		(452.9)
Adjustment to insurance liabilities	(25.8)		(489.8)
Unrecognized net loss related to deferred compensation plan	(5.5)		(7.9)
Deferred income tax liabilities	(383.6)		(655.3)
Accumulated other comprehensive income	698.1		1,197.4
Reduction to Present Value of Future Profits Due to Unrealized Gains That Would Result in Premium Deficiency if Unrealized Gains Were Realized	(151.4)
Reduction to Deferred Acquisition Costs Due to Unrealized Gains That Would Result in Premium Deficiency if Unrealized Gains Were Realized	(146.8)
Increase to insurance liabilities due to unrealized gains that would result in premium deficiency if unrealized gains were realized	25.8		489.8
Increase to Deferred Tax Assets Due to Unrealized Gains That Would Result in Premium Deficiency if Unrealized Gains Were Realized	116.6
Available-for-sale Debt Securities Amortized Cost Basis	22,023.7
Available-for-sale Securities, Gross Unrealized Gains	1,786.7
Available-for-sale Securities, Gross Unrealized Losses	(187.4)
Available-for-sale Securities, Fair Value Disclosure	23,623.0
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities	(4.8)
Available-for-sale Securities, Debt Maturities [Abstract]
Available-for-sale Securities, Debt Maturities, within One Year, Amortized Cost Basis	246.1
Available-for-sale Securities, Debt Maturities, within One Year, Fair Value	250.1
Available-for-sale Securities, Debt Maturities, after One Through Five Years, Amortized Cost Basis	1,823.0
Available-for-sale Securities, Debt Maturities, after One Through Five Years, Fair Value	1,974.9
Available-for-sale Securities, Debt Maturities, after Five Through Ten Years, Amortized Cost Basis	4,131.4
Available-for-sale Securities, Debt Maturities, after Five Through Ten Years, Fair Value	4,468.3
Available-for-sale Securities, Debt Maturities, after Ten Years, Amortized Cost Basis	10,825.2
Available-for-sale Securities, Debt Maturities, after Ten Years, Fair Value	11,628.8
Available For Sale Securities, Debt Maturities, Amortized Cost, Subtotal	17,025.7
Available For Sale Securities, Debt Maturities, Fair Value, Subtotal	18,322.1
Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Amortized Cost Basis	4,998.0
Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Fair Value	5,300.9
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis	22,023.7		21,626.8
Available-for-sale Securities, Debt Securities	23,623.0		24,614.1
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	3,292.8		479.4
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses	(170.5)		(14.2)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	185.5		429.2
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	(16.9)		(18.7)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	3,478.3		908.6
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	(187.4)		(32.9)
Corporate securities [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Available-for-sale Debt Securities Amortized Cost Basis	14,952.8
Available-for-sale Securities, Gross Unrealized Gains	1,294.4
Available-for-sale Securities, Gross Unrealized Losses	(143.4)
Available-for-sale Securities, Fair Value Disclosure	16,103.8
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities	0
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	2,388.2		338.1
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses	(135.5)		(11.2)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	71.7		174.5
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	(7.9)		(9.0)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	2,459.9		512.6
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	(143.4)		(20.2)
US Treasury and Government [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Available-for-sale Debt Securities Amortized Cost Basis	127.9
Available-for-sale Securities, Gross Unrealized Gains	3.6
Available-for-sale Securities, Gross Unrealized Losses	(0.4)
Available-for-sale Securities, Fair Value Disclosure	131.1
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities	0
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	24.0
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses	(0.4)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	24.0
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	(0.4)
US States and Political Subdivisions Debt Securities [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Available-for-sale Debt Securities Amortized Cost Basis	1,945.0
Available-for-sale Securities, Gross Unrealized Gains	162.8
Available-for-sale Securities, Gross Unrealized Losses	(20.6)
Available-for-sale Securities, Fair Value Disclosure	2,087.2
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities	0
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	276.8		48.3
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses	(14.0)		(1.8)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	63.4		68.7
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	(6.6)		(3.4)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	340.2		117.0
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	(20.6)		(5.2)
Asset-backed Securities [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Available-for-sale Debt Securities Amortized Cost Basis	1,389.0
Available-for-sale Securities, Gross Unrealized Gains	79.1
Available-for-sale Securities, Gross Unrealized Losses	(12.7)
Available-for-sale Securities, Fair Value Disclosure	1,455.4
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities	0
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	297.3		41.7
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses	(10.6)		(0.3)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	42.5		111.6
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	(2.1)		(4.9)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	339.8		153.3
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	(12.7)		(5.2)
Collateralized Debt Obligations [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Available-for-sale Debt Securities Amortized Cost Basis	319.4
Available-for-sale Securities, Gross Unrealized Gains	9.2
Available-for-sale Securities, Gross Unrealized Losses	(0.8)
Available-for-sale Securities, Fair Value Disclosure	327.8
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities	0
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	46.5		19.4
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses	(0.8)		(0.4)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	0		32.5
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	0		(0.6)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	46.5		51.9
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	(0.8)		(1.0)
Commercial Mortgage Backed Securities [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Available-for-sale Debt Securities Amortized Cost Basis	1,302.6
Available-for-sale Securities, Gross Unrealized Gains	101.8
Available-for-sale Securities, Gross Unrealized Losses	(6.7)
Available-for-sale Securities, Fair Value Disclosure	1,397.7
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities	0
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	107.0		4.9
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses	(6.4)		(0.1)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	3.3		6.2
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	(0.3)		(0.5)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	110.3		11.1
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	(6.7)		(0.6)
Mortgage Pass Through Securities [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Available-for-sale Debt Securities Amortized Cost Basis	14.8
Available-for-sale Securities, Gross Unrealized Gains	0.8
Available-for-sale Securities, Gross Unrealized Losses	0
Available-for-sale Securities, Fair Value Disclosure	15.6
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities	0
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	1.8		0
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses	0		0
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	1.8		1.9
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	0		0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	3.6		1.9
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	0		0
Collateralized Mortgage Backed Securities [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Available-for-sale Debt Securities Amortized Cost Basis	1,972.2
Available-for-sale Securities, Gross Unrealized Gains	135.0
Available-for-sale Securities, Gross Unrealized Losses	(2.8)
Available-for-sale Securities, Fair Value Disclosure	2,104.4
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities	(4.8)
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	151.2		27.0
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses	(2.8)		(0.4)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	2.8		33.8
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	0		(0.3)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	154.0		60.8
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	(2.8)		(0.7)
Equity Securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	31.7		17.8
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses	(1.3)		(1.6)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	0		0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	0		0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	31.7		17.8
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	$ (1.3)		$ (1.6)

[1] The present value of future profits is the value assigned to the right to receive future cash flows from contracts existing at September 10, 2003 (the date our Predecessor emerged from bankruptcy).