LIABILITIES FOR INSURANCE PRODUCTS (SUMMARY OF LIABILITIES FOR UNPAID CLAIMS ADJUSTMENT EXPENSE) (Details) - Accident and Health Insurance Product Line [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Balance, beginning of year	$ 1,731.8	$ 1,679.5	$ 1,710.1
Less reinsurance receivables (payables)	130.0	125.0	164.1
Net balance, beginning of year	1,601.8	1,554.5	1,546.0
Incurred claims related to:
Current year	1,526.4	1,481.0	1,468.1
Prior years	96.6	(13.3)	(39.9)
Total incurred	1,623.0	1,467.7	1,428.2
Interest on claim reserves	75.3	71.0	70.5
Paid claims related to:
Current year	837.2	841.8	848.7
Prior years	671.3	649.6	641.5
Total paid	1,508.5	1,491.4	1,490.2
Net balance, end of year	1,791.6	1,601.8	1,554.5
Add reinsurance receivables (payables)	(14.0)	130.0	125.0
Balance, end of year	$ 1,777.6	$ 1,731.8	$ 1,679.5