Benefits (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended
	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2014 Pension Plan [Member]	Sep. 30, 2013 Pension Plan [Member]	Sep. 30, 2014 Pension Plan [Member]	Sep. 30, 2013 Pension Plan [Member]	Sep. 30, 2014 Other Postretirement Benefit Plan [Member]	Sep. 30, 2013 Other Postretirement Benefit Plan [Member]	Sep. 30, 2014 Other Postretirement Benefit Plan [Member]	Sep. 30, 2013 Other Postretirement Benefit Plan [Member]
Net Periodic Benefit Cost
Service cost			$ 2.6	$ 3.7	$ 7.6	$ 11.0	$ 2.1	$ 2.5	$ 6.4	$ 7.5
Interest cost			17.0	15.1	51.1	45.3	4.4	3.9	13.3	11.7
Expected return on plan assets			(24.7)	(23.9)	(74.0)	(71.8)	(5.9)	(5.4)	(17.8)	(16.0)
Amortization of:
Transition obligation							0	0	0	0
Prior service cost (credit)			0.6	0.5	1.6	1.7	(0.4)	(0.5)	(1.3)	(1.5)
Actuarial loss			9.1	13.6	27.5	40.8	0.3	1.0	0.9	2.8
Net Periodic Benefit Cost			4.6	9.0	13.8	27.0	0.5	1.5	1.5	4.5
Benefits (Textuals) [Abstract]
Pension and Other Postretirement Benefit Contributions	0
Estimated liability of Postemployment benefits	$ 4.2	$ 4.2