PENSION PLANS AND RETIREMENT BENEFITS (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
PENSION PLANS AND RETIREMENT BENEFITS [Abstract]
Contribution to an individual retirement account as a percentage of employee's eligible compensation under age 45 (in hundredths)	5.00%
Contribution to an individual retirement account as a percentage of employee's eligible compensation age 45 and older (in hundredths)	7.50%
Defined contribution pension plans expense	$ 3.6	$ 3.6
Components of Net Periodic Benfit (Income) Cost
Employer's contribution to defined benefit pension	0.2	0.2
Pension Benefits [Member]
Components of Net Periodic Benfit (Income) Cost
Service cost	1.5	1.6
Interest cost	23.5	23.7
Expected return on plans' assets	(34.2)	(34.9)
Amortization of prior service cost	0	0.1
Recognized actuarial loss	4.3	3.9
Net periodic benefit (income) cost	(4.9)	(5.6)
Other Postretirement Benefits [Member]
Components of Net Periodic Benfit (Income) Cost
Service cost	0.4	0.4
Interest cost	0.9	0.9
Expected return on plans' assets	0	0
Amortization of prior service cost	0	(0.1)
Recognized actuarial loss	0.9	0.7
Net periodic benefit (income) cost	$ 2.2	$ 1.9