Defined Benefit Pension Plans (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	$ 0.9	$ 0.8	$ 1.8	$ 1.6
Interest cost	3.7	4.0	7.4	8.0
Expected return on plan assets	(4.3)	(4.5)	(8.6)	(9.0)
Amortization of prior service cost	0.1	0.1	0.2	0.2
Amortization of net loss	1.7	1.1	3.4	2.2
Net periodic pension cost	2.1	1.5	4.2	3.0
Pension expense		3.0	4.2
Pension Contributions			0.5
Defined Benefit Plan, Expected Future Benefit Payments in Year One	$ 0.5		$ 0.5