SUPPLEMENTAL CASH FLOW INFORMATION (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended	12 Months Ended
	Sep. 30, 2014	Dec. 31, 2013	Dec. 31, 2012
Supplemental Cash Flow Elements [Abstract]
Interest paid, net of amount capitalized	$ 9.6	$ 13.5	$ 13.5
Income taxes paid	20.4	23.1	16.8
Interest expense on affiliated company debt, net	0	0	0.3
Accrued property, plant and equipment costs	$ 5.0	$ 5.5	$ 3.5