FAIR VALUE MEASUREMENTS (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2016	Mar. 31, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Transfers in (out) between levels	$ 0.0		$ 0.0	$ 0.0
Fair value of total debt			133.4		$ 144.3
Carrying amount of long-term debt			130.5		141.2
Impairment charges		$ 108.6		$ 106.0
Decrease in impairment charge	$ (2.6)
Investments held in Rabbi Trust [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities carrying amount			1.7		1.7
Investments held in Rabbi Trust [Member] | SERP [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross unrealized gains associated with the investment held in the rabbi trust			0.2		0.7
Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets accounted at fair value			$ 0.0		$ 0.0