Retirement Benefits (Details 5) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010
Investments measured at fair value
Defined benefit plan fair value of plan assets	$ 3,213.3	$ 2,572.9
Fair Value, Inputs, Level 1 [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets	1,168.9	960.5
Fair Value, Inputs, Level 2 [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets	1,864.1	1,442.6
Fair Value, Inputs, Level 3 [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets	180.3	169.8	149.2
Cash [Member] | US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets	0.4	0.4
Cash [Member] | Non US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets	26.8	32.2
Cash [Member] | Fair Value, Inputs, Level 1 [Member] | US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets	0.4	0.4
Cash [Member] | Fair Value, Inputs, Level 1 [Member] | Non US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets	26.8	32.2
Cash [Member] | Fair Value, Inputs, Level 2 [Member] | US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets
Cash [Member] | Fair Value, Inputs, Level 2 [Member] | Non US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets
Cash [Member] | Fair Value, Inputs, Level 3 [Member] | US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets
Cash [Member] | Fair Value, Inputs, Level 3 [Member] | Non US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets
Common Stock [Member] | US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets	653.7	504.0
Common Stock [Member] | Non US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets	39.3	31.5
Common Stock [Member] | Fair Value, Inputs, Level 1 [Member] | US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets	653.7	504.0
Common Stock [Member] | Fair Value, Inputs, Level 1 [Member] | Non US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets	39.3	31.5
Common Stock [Member] | Fair Value, Inputs, Level 2 [Member] | US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets
Common Stock [Member] | Fair Value, Inputs, Level 2 [Member] | Non US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets
Common Stock [Member] | Fair Value, Inputs, Level 3 [Member] | US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets
Common Stock [Member] | Fair Value, Inputs, Level 3 [Member] | Non US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets
Equity Funds [Member] | US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets	160.0	144.2
Equity Funds [Member] | Fair Value, Inputs, Level 1 [Member] | US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets	160.0	144.2
Equity Funds [Member] | Fair Value, Inputs, Level 2 [Member] | US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets
Equity Funds [Member] | Fair Value, Inputs, Level 3 [Member] | US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets
Equity Common Collective Trust [Member] | US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets	530.5	317.5
Equity Common Collective Trust [Member] | Non US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets	296.9	257.8
Equity Common Collective Trust [Member] | Fair Value, Inputs, Level 1 [Member] | US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets
Equity Common Collective Trust [Member] | Fair Value, Inputs, Level 1 [Member] | Non US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets
Equity Common Collective Trust [Member] | Fair Value, Inputs, Level 2 [Member] | US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets	530.5	317.5
Equity Common Collective Trust [Member] | Fair Value, Inputs, Level 2 [Member] | Non US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets	296.9	257.8
Equity Common Collective Trust [Member] | Fair Value, Inputs, Level 3 [Member] | US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets
Equity Common Collective Trust [Member] | Fair Value, Inputs, Level 3 [Member] | Non US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets
Corporate Debt [Member] | US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets	525.9	347.6
Corporate Debt [Member] | Non US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets	68.7	52.1
Corporate Debt [Member] | Fair Value, Inputs, Level 1 [Member] | US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets
Corporate Debt [Member] | Fair Value, Inputs, Level 1 [Member] | Non US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets
Corporate Debt [Member] | Fair Value, Inputs, Level 2 [Member] | US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets	525.9	347.6
Corporate Debt [Member] | Fair Value, Inputs, Level 2 [Member] | Non US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets	68.7	52.1
Corporate Debt [Member] | Fair Value, Inputs, Level 3 [Member] | US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets
Corporate Debt [Member] | Fair Value, Inputs, Level 3 [Member] | Non US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets
Government Securities [Member] | US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets	368.4	268.9
Government Securities [Member] | Fair Value, Inputs, Level 1 [Member] | US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets	287.9	246.3
Government Securities [Member] | Fair Value, Inputs, Level 2 [Member] | US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets	80.5	22.6
Government Securities [Member] | Fair Value, Inputs, Level 3 [Member] | US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets
Foreign Government Debt Securities [Member] | Non US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets	0.8	1.9
Foreign Government Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member] | Non US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets	0.8	1.9
Foreign Government Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member] | Non US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets
Foreign Government Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member] | Non US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets
Fixed Income Common Collective Trust [Member] | US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets	145.5	237.5
Fixed Income Common Collective Trust [Member] | Non US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets	167.1	161.0
Fixed Income Common Collective Trust [Member] | Fair Value, Inputs, Level 1 [Member] | US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets
Fixed Income Common Collective Trust [Member] | Fair Value, Inputs, Level 1 [Member] | Non US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets
Fixed Income Common Collective Trust [Member] | Fair Value, Inputs, Level 2 [Member] | US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets	145.5	237.5
Fixed Income Common Collective Trust [Member] | Fair Value, Inputs, Level 2 [Member] | Non US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets	167.1	161.0
Fixed Income Common Collective Trust [Member] | Fair Value, Inputs, Level 3 [Member] | US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets
Fixed Income Common Collective Trust [Member] | Fair Value, Inputs, Level 3 [Member] | Non US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets
Private Equity Investments [Member] | US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets	83.2	85.0
Private Equity Investments [Member] | Fair Value, Inputs, Level 1 [Member] | US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets
Private Equity Investments [Member] | Fair Value, Inputs, Level 2 [Member] | US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets
Private Equity Investments [Member] | Fair Value, Inputs, Level 3 [Member] | US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets	83.2	85.0	62.2
Alternative Equity Investments [Member] | US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets	53.4	49.0
Alternative Equity Investments [Member] | Fair Value, Inputs, Level 1 [Member] | US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets
Alternative Equity Investments [Member] | Fair Value, Inputs, Level 2 [Member] | US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets
Alternative Equity Investments [Member] | Fair Value, Inputs, Level 3 [Member] | US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets	53.4	49.0	46.3
Real Estate [Member] | Non US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets	46.2	46.1
Real Estate [Member] | Fair Value, Inputs, Level 1 [Member] | Non US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets
Real Estate [Member] | Fair Value, Inputs, Level 2 [Member] | Non US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets	46.2	42.2
Real Estate [Member] | Fair Value, Inputs, Level 3 [Member] | Non US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets		3.9	3.9
Insurance Contracts [Member] | US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets	0.8	0.9
Insurance Contracts [Member] | Non US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets	38.5	26.9
Insurance Contracts [Member] | Fair Value, Inputs, Level 1 [Member] | US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets
Insurance Contracts [Member] | Fair Value, Inputs, Level 1 [Member] | Non US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets
Insurance Contracts [Member] | Fair Value, Inputs, Level 2 [Member] | US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets
Insurance Contracts [Member] | Fair Value, Inputs, Level 2 [Member] | Non US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets
Insurance Contracts [Member] | Fair Value, Inputs, Level 3 [Member] | US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets	0.8	0.9	0.9
Insurance Contracts [Member] | Fair Value, Inputs, Level 3 [Member] | Non US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets	38.5	26.9	28.5
Other Pension Plan Investments [Member] | Non US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets	7.2	8.4
Other Pension Plan Investments [Member] | Fair Value, Inputs, Level 1 [Member] | Non US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets
Other Pension Plan Investments [Member] | Fair Value, Inputs, Level 2 [Member] | Non US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets	2.8	4.3
Other Pension Plan Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Non US Pension Benefit Plans [Member]
Investments measured at fair value
Defined benefit plan fair value of plan assets	$ 4.4	$ 4.1	$ 7.4