Retirement Benefits (Details 6) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Plan assets at end of year	$ 3,213.3	$ 2,572.9
Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Plan assets at beginning of year	169.8	149.2
Realized Gain	22.4	10.2
Unrealized Gains (Losses)	(2.7)	14.6
Purchases sales issuances, and settlements, net	(9.2)	(4.2)
Plan assets at end of year	180.3	169.8
Other Pension Plan Investments [Member] | Non US Pension Benefit Plans [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Plan assets at end of year	7.2	8.4
Other Pension Plan Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Non US Pension Benefit Plans [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Plan assets at beginning of year	4.1	7.4
Realized Gain
Unrealized Gains (Losses)	0.1	0.2
Purchases sales issuances, and settlements, net	0.2	(3.5)
Plan assets at end of year	4.4	4.1
Private Equity Investments [Member] | US Pension Benefit Plans [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Plan assets at end of year	83.2	85.0
Private Equity Investments [Member] | Fair Value, Inputs, Level 3 [Member] | US Pension Benefit Plans [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Plan assets at beginning of year	85.0	62.2
Realized Gain	18.0	3.2
Unrealized Gains (Losses)	(9.3)	13.3
Purchases sales issuances, and settlements, net	(10.5)	6.3
Plan assets at end of year	83.2	85.0
Alternative Equity Investments [Member] | US Pension Benefit Plans [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Plan assets at end of year	53.4	49.0
Alternative Equity Investments [Member] | Fair Value, Inputs, Level 3 [Member] | US Pension Benefit Plans [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Plan assets at beginning of year	49.0	46.3
Realized Gain	4.4	7.0
Unrealized Gains (Losses)	(1.4)	5.8
Purchases sales issuances, and settlements, net	1.4	(10.1)
Plan assets at end of year	53.4	49.0
Real Estate [Member] | Non US Pension Benefit Plans [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Plan assets at end of year	46.2	46.1
Real Estate [Member] | Fair Value, Inputs, Level 3 [Member] | Non US Pension Benefit Plans [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Plan assets at beginning of year	3.9	3.9
Realized Gain
Unrealized Gains (Losses)
Purchases sales issuances, and settlements, net	(3.9)
Plan assets at end of year		3.9
Insurance Contracts [Member] | US Pension Benefit Plans [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Plan assets at end of year	0.8	0.9
Insurance Contracts [Member] | Non US Pension Benefit Plans [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Plan assets at end of year	38.5	26.9
Insurance Contracts [Member] | Fair Value, Inputs, Level 3 [Member] | US Pension Benefit Plans [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Plan assets at beginning of year	0.9	0.9
Realized Gain
Unrealized Gains (Losses)
Purchases sales issuances, and settlements, net	(0.1)
Plan assets at end of year	0.8	0.9
Insurance Contracts [Member] | Fair Value, Inputs, Level 3 [Member] | Non US Pension Benefit Plans [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Plan assets at beginning of year	26.9	28.5
Realized Gain
Unrealized Gains (Losses)	7.9	(4.7)
Purchases sales issuances, and settlements, net	3.7	3.1
Plan assets at end of year	$ 38.5	$ 26.9