EMPLOYEE BENEFIT PLANS (Details) (USD $) In Millions, unless otherwise specified		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2014 Pension Benefits	Jun. 30, 2013 Pension Benefits	Jun. 30, 2014 Pension Benefits	Jun. 30, 2013 Pension Benefits	Jun. 30, 2014 Other Postretirement Benefits	Jun. 30, 2013 Other Postretirement Benefits	Jun. 30, 2014 Other Postretirement Benefits	Jun. 30, 2013 Other Postretirement Benefits	Jul. 31, 2014 Subsequent Event
Components of net periodic benefit cost (including amounts capitalized to the balance sheets)
Service cost		$ 5.9	$ 7.6	$ 12.5	$ 15.1	$ 4.8	$ 5.9	$ 10.7	$ 12.4
Interest cost		19.3	17.8	39.0	35.6	5.2	6.1	12.3	12.4
Expected return on plan assets		(28.5)	(26.1)	(57.4)	(52.7)	(7.9)	(7.6)	(16.7)	(15.3)
Loss on plan settlement		0.9	0	0.9	0	0	0	0	0
Amortization of prior service cost (credit)		0.1	1.0	0.3	2.0	(2.8)	(0.6)	(4.1)	(1.2)
Amortization of net actuarial loss		8.6	14.8	17.0	28.3	0.8	2.2	1.5	4.2
Net periodic benefit cost		6.3	15.1	12.3	28.3	0.1	6.0	3.7	12.5
Contributions to the plans				69.4				0.1
Expected contributions to the plans during the remainder of fiscal year				3.1				10.9
Expected contributions to the plans during the remainder of the fiscal year from the Rabbi trust				2.0
Rabbi trust funding related to potential change in control	65.0
Rabbi trust funding in July 2014 related to potential change in control										$ 64.8