Pension and Other Post-Retirement Benefits (Details 2) (USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Defined Benefit Pension [Member]
Components of pension and other post retirement benefit costs
Service cost	$ 1.7		$ 1.5		$ 5.1		$ 4.5
Interest cost	4.6		4.9		13.8		14.8
Expected return on plan assets	(6.9)		(7.4)		(20.7)		(22.2)
Amortization of unrecognized prior service credit	(0.3)	[1]	(0.3)	[1]	(0.8)	[1]	(0.8)	[1]
Amortization of unrecognized net actuarial loss (gains)	3.7	[1]	2.5	[1]	11.2	[1]	7.5	[1]
Net costs	2.8		1.2		8.6		3.8
Retiree Health and Life [Member]
Components of pension and other post retirement benefit costs
Service cost	0.1		0.1		0.2		0.2
Interest cost	0.4		0.5		1.2		1.5
Expected return on plan assets	0		0		0		0
Amortization of unrecognized prior service credit	0	[1]	0	[1]	(0.1)	[1]	(0.1)	[1]
Amortization of unrecognized net actuarial loss (gains)	0	[1]	0	[1]	0	[1]	(0.1)	[1]
Net costs	$ 0.5		$ 0.6		$ 1.3		$ 1.5

[1] (a)Amounts are reclassified from accumulated other comprehensive loss.