SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017 USD ($) primary_source	Dec. 31, 2017 USD ($) input_method	Dec. 31, 2016 USD ($)
Valuation of investment securities
Number of primary sources of information used for determining fair value | primary_source	1
Total number of primary sources of information available for determining fair value	3	3
Cash
Negative balances due to outstanding checks and drafts | $	$ 132.7	$ 132.7	$ 79.2