PENSION AND OTHER POST RETIREMENT BENEFIT PLANS (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Pension Benefits
Changes in net periodic benefit cost
Service cost - benefits earned during the period	$ 0.9	$ 0.6
Interest cost on projected benefit obligations	3.9	4.1
Expected return on plan assets	(4.0)	(4.3)
Amortization of net actuarial loss	1.3	0.8
Total net periodic benefit cost	2.1	1.2
Other Benefits
Changes in net periodic benefit cost
Service cost - benefits earned during the period	0.2	0.2
Interest cost on projected benefit obligations	0.3	0.3
Amortization of net actuarial loss	0.5	0.4
Total net periodic benefit cost	$ 1.0	$ 0.9