PENSION AND POSTRETIREMENT PLANS (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended		15 Months Ended	3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012 Defined Benefit Plans [Member]	Mar. 31, 2012 Defined Benefit Plans [Member]	Sep. 30, 2013 Defined Benefit Plans [Member]	Sep. 30, 2012 Defined Benefit Plans [Member]	Sep. 30, 2012 Post-Retirement Medical Plan [Member]	Mar. 31, 2012 Post-Retirement Medical Plan [Member]	Sep. 30, 2013 Post-Retirement Medical Plan [Member]	Sep. 30, 2012 Post-Retirement Medical Plan [Member]
Defined Benefit Plan Disclosures [Line Items]
Pension Contributions		$ 0
Minimum non-elective contribution (NEC) % for the 401(K) plan (in hundredths)		3.00%
Discretionary contribution % for the 401(K) plan, range mininum		1.00%
Discretionary contribution % for the 401(K) plan, range maximum		3.00%
Defined contribution retirement plan cost	12.2	37.3	36.3	12.0
Defined Benefit Plan and Postretirement Plan Disclosure
Service cost for benefits earned					0.7	0.6	1.9	1.8	0.1	0.1	0.3	0.3
Interest cost on benefit obligation					3.7	3.8	11.1	11.2	0.6	0.6	1.9	1.8
Expected return on plan assets					(4.3)	(4.4)	(12.9)	(13.0)
Net amortization and deferral					2.3	3.1	8.3	9.1	0.2	0.1	0.7	0.1
Defined benefit/postretirement plan costs					$ 2.4	$ 3.1	$ 8.4	$ 9.1	$ 0.9	$ 0.8	$ 2.9	$ 2.2