INCOME TAXES (NARRATIVE) (Details) $ in Millions		3 Months Ended	12 Months Ended
	May 08, 2013	Dec. 31, 2016 USD ($) position	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	May 11, 2010	Jan. 20, 2009 right
Operating Loss Carryforwards [Line Items]
Deferred tax assets more likely than not to be realized through future taxable earnings		$ 785.6	$ 785.6	$ 946.6
Deferred tax assets		1,025.8	1,025.8	1,160.1
Valuation allowance		$ 240.2	$ 240.2	213.5	$ 246.0	$ 294.8
Aggregate growth rate for the next five years		3.00%	3.00%
Forecast period of model			5 years
Adjusted average taxable income			$ 335.0
Adjusted average nonlife taxable income			85.0
Adjusted average life taxable income			250.0
Increase (decrease) in valuation allowance			$ (26.7)	32.5	48.8
Loss limitation based on income of life insurance company, percent		35.00%	35.00%
Loss limitation based on loss of non-life entities, percent		35.00%	35.00%
Federal long-term tax exempt rate		1.68%	1.68%
Ownership change threshold restricting NOL usage		50.00%	50.00%
Ownership percentage threshold relating to company 382 securities								4.99%
Number of rights for each share | right								1
Ownership percentage threshold relating to company 382 provision, ownership percentage at which transfers of common stock become void (less than)	4.99%						5.00%
Section 382 Charter amendment, extension term	3 years
Net operating loss carryforwards		$ 2,522.6	$ 2,522.6
Unrecognized tax benefits that would impact effective tax rate		0.0	0.0	155.4
Unrecognized tax benefits, income tax penalties and interest accrued		$ 0.0	0.0	3.2
Number of tax positions settled | position		2
Net state operating loss carryforwards		$ 12.3	$ 12.3	14.1
Future cash tax payments as a percent of life insurance, taxable income due			65.00%
NOL carryforwards related to the deductions for stock options and restricted stock		15.7	$ 15.7
IRS settlement		118.7	(170.4)	0.0	0.0
Reduction in interest recognized from prior periods on alternative minimum tax		3.4
Decrease to income tax accrued			(11.7)	$ 92.9	$ 119.7
Domestic Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Valuation allowance		230.2	230.2
State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Valuation allowance		10.0	10.0
Internal Revenue Service (IRS) [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards		2,500.0	2,500.0
Life Insurance Related NOLs [Member]
Operating Loss Carryforwards [Line Items]
Tax Benefits Recognized On IRS Settlement		280.7
Additional life net operating loss carryforwards		98.2	98.2
Decrease to income tax accrued			(50.0)
Non-Life Insurance Related NOLs [Member]
Operating Loss Carryforwards [Line Items]
Increase (decrease) in valuation allowance		(51.7)
Additional life net operating loss carryforwards		17.1	$ 17.1
Non-Life Insurance Related NOLs, Classification Of Loss On Investment [Member]
Operating Loss Carryforwards [Line Items]
Tax Benefits Recognized On IRS Settlement		130.0
Non-Life Insurance Related NOLs, Bad Debt Deduction On Stock Purchase Loan [Member]
Operating Loss Carryforwards [Line Items]
Tax Benefits Recognized On IRS Settlement		$ 66.7