EMPLOYEE BENEFIT PLANS (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Amounts recognized on the entity's balance sheets related to the funded status of the benefit plans
Long-term liabilities	$ 211.0	$ 625.2
Pension Benefits
Change in benefit obligation
Obligation at January 1	1,784.9	1,563.1
Service cost	30.2	46.0	41.4
Interest cost	71.2	78.0	80.1
Plan amendments	0	0
Actuarial (gain) loss, net	(153.1)	196.6
Participant contributions	0	0
Benefit payments	(91.5)	(98.8)
Federal subsidy on benefits paid	0	0
Obligation at December 31	1,641.7	1,784.9	1,563.1
Change in fair value of plan assets
Fair value of plan assets at January 1	1,348.1	1,099.5
Actual return on plan assets	205.4	173.6
Employer contributions	65.7	173.8
Participant contributions	0	0
Benefit payments	(91.5)	(98.8)
Fair value of plan assets at December 31	1,527.7	1,348.1	1,099.5
Funded status at December 31	(114.0)	(436.8)
Amounts recognized on the entity's balance sheets related to the funded status of the benefit plans
Current liabilities	9.0	7.9
Long-term liabilities	105.0	428.9
Total liabilities	114.0	436.8
Accumulated benefit obligation	1,489.1	1,594.7
Information for pension plans with an accumulated benefit obligation in excess of plan assets
Projected benefit obligation	65.4	1,784.9
Accumulated benefit obligation	63.0	1,594.7
Fair value of plan assets	0	1,348.1
Other Benefits
Change in benefit obligation
Obligation at January 1	621.0	576.8
Service cost	24.9	20.8	19.0
Interest cost	24.8	28.5	29.5
Plan amendments	0.2	0
Actuarial (gain) loss, net	(73.4)	14.3
Participant contributions	10.6	10.6
Benefit payments	(34.0)	(32.1)
Federal subsidy on benefits paid	2.2	2.1
Obligation at December 31	576.3	621.0	576.8
Change in fair value of plan assets
Fair value of plan assets at January 1	424.4	285.5
Actual return on plan assets	57.8	46.3
Employer contributions	11.3	114.1
Participant contributions	10.6	10.6
Benefit payments	(34.0)	(32.1)
Fair value of plan assets at December 31	470.1	424.4	285.5
Funded status at December 31	(106.2)	(196.6)
Amounts recognized on the entity's balance sheets related to the funded status of the benefit plans
Current liabilities	0.2	0.3
Long-term liabilities	106.0	196.3
Total liabilities	$ 106.2	$ 196.6