INVESTMENTS (Narrative) (Details) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2018 USD ($) security	Sep. 30, 2018 USD ($) security	Sep. 30, 2017 USD ($)	Dec. 31, 2017 USD ($) security
Investments [Abstract]
Proceeds from sale of investment securities		$ 161.4	$ 252.1
Unrealized gains and losses for equity securities (Less Than)	$ 1.6	$ 2.6
Debt and equity securities held in an unrealized loss position | security	1,364	1,364		866
Debt securities and equity securities held in an unrealized loss position 12 months or more | security	195	195		73
Fair value of investments deposited with governmental authorities required by law	$ 10.2	$ 10.2		$ 12.9