Employee Benefits (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Pension [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 0.9	$ 0.9	$ 1.9	$ 1.9
Interest cost	1.3	1.2	2.5	2.4
Expected return on plan assets	(1.0)	(0.9)	(2.0)	(1.8)
Amortization of prior service costs	1.3	1.3	2.5	2.6
Amortization of actuarial loss	0.6	0.2	1.2	0.4
Periodic expense	3.1	2.7	6.1	5.5
Pension [Member] | Funded Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Contributions to pension plan			5.4
Expected to contribute to pension plans	2.7		2.7
Pension [Member] | Unfunded Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Contributions to pension plan			0.9
Expected to contribute to pension plans	2.1		2.1
Pension [Member] | Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Expected to contribute to pension plans	0.1		0.1
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	0	0	0	0
Interest cost	0.1	0.1	0.2	0.2
Amortization of prior service costs	0.1	0.1	0.2	0.2
Amortization of actuarial loss	0	0	0	0
Periodic expense	$ 0.2	$ 0.2	$ 0.4	$ 0.4