Retirement Plans Retirement Plans (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Sep. 30, 2012 Rate	Sep. 30, 2011 Rate	Sep. 30, 2010	Sep. 30, 2009
Defined Benefit Plan, Fair Value of Plan Assets	$ 26.5	$ 24.2	$ 24.2	$ 18.9
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, before Tax	2.9	4.6
Defined Contribution Plan, Employers Matching Contribution, Annual Vesting Percentage	100.00%
Defined Contribution Plan, Employer Discretionary Contribution Amount	3.7	2.8	2.1
Defined Benefit Plan, Actual Plan Asset Allocations	100.00%	100.00%
Other Comprehensive Income (Loss), Reclassification, Pension and Other Postretirement Benefit Plans, Net Gain (Loss) Recognized in Net Periodic Benefit Cost, before Tax	(0.4)	0
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	4.80%	5.30%	5.90%
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	3.80%	4.80%
Defined Benefit Plan, Accumulated Benefit Obligation	42.8	39.0
Defined Benefit Plan, Amounts Recognized in Balance Sheet	(16.4)	(15.0)
Defined Benefit Plan, Benefit Obligation	42.8	39.0	37.6	35.6
Defined Benefit Plan, Service Cost	0	0	0
Defined Benefit Plan, Interest Cost	1.8	1.9	2.0
Defined Benefit Plan, Actuarial Gain (Loss)	5.8	2.6	2.8
Defined Benefit Plan, Expected Future Benefit Payments, Total	26.5
Defined Benefit Plan, Actual Return on Plan Assets	4.6	(0.4)	1.7
Defined Benefit Plan, Contributions by Employer	1.5	3.5	6.4
Defined Benefit Plan, Benefits Paid	(3.8)	(3.1)	(2.8)
Defined Benefit Plan, Funded Status of Plan	(16.3)	(14.8)	(13.4)
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, Net of Tax	6.2	4.6
Pension and Other Postretirement Benefit Plans, Amounts that Will be Amortized from Accumulated Other Comprehensive Income (Loss) in Next Fiscal Year	0.8
Defined Benefit Plan, Estimated Future Employer Contributions in Next Fiscal Year	2.5
Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets, Aggregate Projected Benefit Obligation	42.8	39.0
Defined Benefit Plan, Expected Return on Plan Assets	(1.7)	(1.7)	(1.7)
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Return on Assets	7.30%	7.30%	8.25%
Defined Benefit Plan, Amortization of Gains (Losses)	0.4	0	0
Defined Benefit Plan, Net Periodic Benefit Cost	0.5	0.2	0.3
Defined Benefit Plan, Estimated Future Employer Contributions in Next Fiscal Year	4.3
Defined Benefit Plan, Expected Future Benefit Payments, Year Two	3.7
Defined Benefit Plan, Expected Future Benefit Payments, Year Three	3.3
Defined Benefit Plan, Expected Future Benefit Payments, Year Four	3.2
Defined Benefit Plan, Expected Future Benefit Payments, Year Five	2.8
Defined Benefit Plan, Expected Future Benefit Payments, Five Fiscal Years Thereafter	9.2
Weighted Average Discount Rate, Percent	7.00%	7.30%
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss), Net Gain (Loss), before Tax	2.5	4.6
Defined Benefit Plan, Amounts Recognized in Net Periodic Benefit Cost and Other Comprehensive Income (Loss), Net Gain (Loss), before Tax	3.0	4.8
Debt Securities [Member]
Defined Benefit Plan, Actual Plan Asset Allocations	34.00%	30.00%
Defined Benefit Plan, Target Allocation Percentage	0.3
Equity Securities [Member]
Defined Benefit Plan, Actual Plan Asset Allocations	66.00%	70.00%
Defined Benefit Plan, Target Allocation Percentage	0.7
Other Assets [Member]
Defined Benefit Plan, Amounts Recognized in Balance Sheet	0.1	0.2
Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan, Fair Value of Plan Assets	0	0.2
Fair Value, Inputs, Level 1 [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Fair Value, Inputs, Level 1 [Member] | US Treasury and Government [Member]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Fair Value, Inputs, Level 1 [Member] | Mutual funds and other [Member]
Defined Benefit Plan, Fair Value of Plan Assets		0.2
Fair Value, Inputs, Level 1 [Member] | Debt Securities [Member]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Fair Value, Inputs, Level 1 [Member] | Equity Securities [Member]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Fair Value, Inputs, Level 1 [Member] | Real Estate [Member]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Fair Value of Plan Assets	26.5	24.6
Fair Value, Inputs, Level 2 [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan, Fair Value of Plan Assets	0.4	0.5
Fair Value, Inputs, Level 2 [Member] | US Treasury and Government [Member]
Defined Benefit Plan, Fair Value of Plan Assets	0.8	0.9
Fair Value, Inputs, Level 2 [Member] | Mutual funds and other [Member]
Defined Benefit Plan, Fair Value of Plan Assets		0
Fair Value, Inputs, Level 2 [Member] | Debt Securities [Member]
Defined Benefit Plan, Fair Value of Plan Assets	7.7	6.0
Fair Value, Inputs, Level 2 [Member] | Equity Securities [Member]
Defined Benefit Plan, Fair Value of Plan Assets	16.6	15.5
Fair Value, Inputs, Level 2 [Member] | Real Estate [Member]
Defined Benefit Plan, Fair Value of Plan Assets	1.0	1.7
Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan, Fair Value of Plan Assets	0	0	1.3
Fair Value, Inputs, Level 3 [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Fair Value, Inputs, Level 3 [Member] | US Treasury and Government [Member]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Fair Value, Inputs, Level 3 [Member] | Mutual funds and other [Member]
Defined Benefit Plan, Fair Value of Plan Assets		0
Fair Value, Inputs, Level 3 [Member] | Debt Securities [Member]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Fair Value, Inputs, Level 3 [Member] | Equity Securities [Member]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Fair Value, Inputs, Level 3 [Member] | Real Estate [Member]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Estimate of Fair Value, Fair Value Disclosure [Member]
Defined Benefit Plan, Fair Value of Plan Assets	26.5	24.8
Estimate of Fair Value, Fair Value Disclosure [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan, Fair Value of Plan Assets	0.4	0.5
Estimate of Fair Value, Fair Value Disclosure [Member] | US Treasury and Government [Member]
Defined Benefit Plan, Fair Value of Plan Assets	0.8	0.9
Estimate of Fair Value, Fair Value Disclosure [Member] | Mutual funds and other [Member]
Defined Benefit Plan, Fair Value of Plan Assets		0.2
Estimate of Fair Value, Fair Value Disclosure [Member] | Debt Securities [Member]
Defined Benefit Plan, Fair Value of Plan Assets	7.7	6.0
Estimate of Fair Value, Fair Value Disclosure [Member] | Equity Securities [Member]
Defined Benefit Plan, Fair Value of Plan Assets	16.6	15.5
Estimate of Fair Value, Fair Value Disclosure [Member] | Real Estate [Member]
Defined Benefit Plan, Fair Value of Plan Assets	$ 1.0	$ 1.7
Savings Incentive Match Plan for Employees IRA [Member]
Defined Contribution Plan, Maximum Annual Contribution Per Employee, Percent	100.00%
Defined Contribution Plan, Employer Matching Contribution, Percent	3.00%
Defined Contribution Plan, Employers Matching Contribution, Annual Vesting Percentage	100.00%
UK Plan [Member]
Defined Contribution Plan, Employers Matching Contribution, Annual Vesting Percentage	100.00%
UK Plan [Member] | Maximum [Member]
Defined Contribution Plan, Employer Matching Contribution, Percent	10.00%
401k Plan [Member]
Defined Contribution Plan, Employer Matching Contribution, Percent	62.50%
Defined Contribution Plan, Employers Matching Contribution, Annual Vesting Percentage	8.00%
Defined Contribution Plan, Employers Matching Contribution, Annual Vesting Percentage, Two to Three Years	20.00%
Defined Contribution Plan, Employers Matching Contribution, Annual Vesting Percentage, Three to Four Years	40.00%
Defined Contribution Plan, Employers Matching Contribution, Annual Vesting Percentage, Four to Five Years	60.00%
Defined Contribution Plan, Employers Matching Contribution, Annual Vesting Percentage, All Years	100.00%
401k Plan [Member] | Maximum [Member]
Defined Contribution Plan, Maximum Annual Contribution Per Employee, Percent	80.00%
401k Plan [Member] | Minimum [Member]
Defined Contribution Plan, Maximum Annual Contribution Per Employee, Percent	1.00%