INVESTMENTS (Narrative) (Details) $ in Millions	6 Months Ended
	Jun. 30, 2018 USD ($) security	Jun. 30, 2017 USD ($)	Dec. 31, 2017 USD ($) security
Investments [Abstract]
Proceeds from sale of investment securities	$ 134.8	$ 142.0
Unrealized gains and losses for equity securities (Less Than)	$ 1.0
Debt and equity securities held in an unrealized loss position | security	1,340		866
Debt securities and equity securities held in an unrealized loss position 12 months or more | security	55		73
Fair value of investments deposited with governmental authorities required by law	$ 10.2		$ 12.9