Benefit Plans (Components Of Net Periodic Benefit Cost) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 0.9	$ 1.7	$ 1.6
Interest cost	4.6	6.9	6.8
Expected return on plan assets	(4.3)	(5.1)	(6.3)
Amortization of prior service cost	0	0	0.4
Recognized actuarial loss (gain)	0	0.7	1.4
Settlement (gain) loss	0	24.3	(0.7)
Net periodic benefit cost	1.2	28.5	3.2
Nonpension Postretirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	0.4	0.3	0.3
Interest cost	1.3	1.3	1.2
Expected return on plan assets	0	0	0
Amortization of prior service cost	0.1	0.1	0.1
Recognized actuarial loss (gain)	0	0	0
Settlement (gain) loss	0	0	0
Net periodic benefit cost	$ 1.8	$ 1.7	$ 1.6