Pension And Other Postretirement Benefits (Pension Plan Assets Measured At Fair Value On A Recurring Basis) (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2009
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets measured at fair value on a recurring basis	$ 241.2	$ 212.9
Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets measured at fair value on a recurring basis	0.6
Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets measured at fair value on a recurring basis	235.2	208.3
Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets measured at fair value on a recurring basis	5.4
Partnership/Joint Venture Interests [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets measured at fair value on a recurring basis	5.4	4.6	3.5
Partnership/Joint Venture Interests [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets measured at fair value on a recurring basis	5.4
Cash & Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets measured at fair value on a recurring basis	0.6
Cash & Cash Equivalents [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets measured at fair value on a recurring basis	0.6
Real Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets measured at fair value on a recurring basis	17.1
Real Assets [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets measured at fair value on a recurring basis	17.1
Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets measured at fair value on a recurring basis	117.5	151.0
Equities [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets measured at fair value on a recurring basis	117.5	151.0
Mutual Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets measured at fair value on a recurring basis	235.2	208.3
Mutual Funds [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets measured at fair value on a recurring basis	235.2	208.3
Mutual Funds [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets measured at fair value on a recurring basis	100.6	57.3
Mutual Funds [Member] | Fixed Income [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets measured at fair value on a recurring basis	$ 100.6	$ 57.3