Pension and Other Postretirement Benefits (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		1 Months Ended	10 Months Ended	1 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013 Pension Plans, Defined Benefit [Member]	Sep. 30, 2012 Pension Plans, Defined Benefit [Member]	Sep. 30, 2013 Pension Plans, Defined Benefit [Member]	Sep. 30, 2012 Pension Plans, Defined Benefit [Member]	Sep. 30, 2013 Other Postretirement Benefit Plans, Defined Benefit [Member]	Sep. 30, 2012 Other Postretirement Benefit Plans, Defined Benefit [Member]	Sep. 30, 2013 Other Postretirement Benefit Plans, Defined Benefit [Member]	Sep. 30, 2012 Other Postretirement Benefit Plans, Defined Benefit [Member]	Oct. 31, 2013 Subsequent Event [Member] Pension Plans, Defined Benefit [Member]	Oct. 31, 2013 Subsequent Event [Member] Pension Plans, Defined Benefit [Member]	Jul. 31, 2013 Butler and Zanesville Works Retiree Healthcare Benefits Litigation [Member] Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension plan contributions			$ 140.2	$ 170.2			$ 140.2						$ 40.9	$ 181.1
Contributions to retirees VEBAs															30.8
Net periodic benefit cost (income) [Abstract]
Service cost					0.7	0.8	1.9	2.4	1.1	1.2	3.5	3.4
Interest cost					34.7	40.1	104.1	120.2	5.3	7.9	15.8	23.7
Expected return on assets					(46.2)	(47.4)	(138.3)	(141.0)
Amortization of prior service cost (credit)					0.9	1.1	2.7	3.0	(20.0)	(19.4)	(60.0)	(58.0)
Amortization of (gain) loss					6.7	6.1	20.0	18.3	0.7	0	1.8	0
Settlement (gain)					(0.8)	0	(0.8)	0
Net periodic benefit cost (income)	$ (16.9)	$ (9.6)	$ (49.3)	$ (28.0)	$ (4.0)	$ 0.7	$ (10.4)	$ 2.9	$ (12.9)	$ (10.3)	$ (38.9)	$ (30.9)