BUSINESS SEGMENTS (SCHEDULE OF SELECTED FINANCIAL INFORMATION, BY SEGMENT) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Present value of future profits	$ 343.6	$ 359.6	$ 401.8	$ 449.0
Deferred acquisition costs	1,322.5	1,026.8
Insurance liabilities	23,456.7	23,539.0
Bankers Life:
Segment Reporting Information [Line Items]
Present value of future profits	86.5	81.1
Deferred acquisition costs	863.2	606.5
Insurance liabilities	13,714.6	13,257.2
Washington National:
Segment Reporting Information [Line Items]
Present value of future profits	226.9	243.7
Deferred acquisition costs	342.7	310.8
Insurance liabilities	5,556.1	5,590.7
Colonial Penn:
Segment Reporting Information [Line Items]
Present value of future profits	30.2	34.8
Deferred acquisition costs	116.6	109.5
Insurance liabilities	845.7	834.4
Long-term care
Segment Reporting Information [Line Items]
Present value of future profits	0.0	0.0
Deferred acquisition costs	0.0	0.0
Insurance liabilities	$ 3,340.3	$ 3,856.7