Annual report pursuant to Section 13 and 15(d)

Retirement Benefits - Pension Plans and Defined Contribution Plans (Details)

v3.22.2.2
Retirement Benefits - Pension Plans and Defined Contribution Plans (Details) - USD ($)
$ in Millions
3 Months Ended 12 Months Ended
Sep. 30, 2022
Sep. 30, 2021
Sep. 30, 2022
Sep. 30, 2021
Sep. 30, 2020
Cash Flows          
Cash contribution to defined benefit retirement plans     $ 10.5 $ 11.6 $ 12.4
Defined Contribution Plans          
Employer's contribution to defined contribution plans (as a percent)     4.00%    
Expenses related to defined contribution plans     $ 16.1 15.7 15.3
Minimum          
Defined Contribution Plans          
Contribution vesting period     0 years    
Maximum          
Defined Contribution Plans          
Employer's matching contribution to defined contribution plans (as a percent)     6.00%    
Contribution vesting period     5 years    
Other Postretirement Benefits Plan          
Fair Value Measurements          
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)     $ (1.6) 0.2  
Other Postretirement Benefits Cost (Reversal of Cost)     0.3 0.2 0.1
Cash Flows          
Estimated cash contribution to defined benefit retirement plans $ 0.7   0.7    
Pension Plans Defined Benefit          
Cash Flows          
Cash contribution to defined benefit retirement plans     10.0 $ 11.0 $ 10.0
Pension Plans Defined Benefit | Minimum          
Cash Flows          
Estimated cash contribution to defined benefit retirement plans 9.5   $ 9.5    
United States          
Fair Value Measurements          
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate     3.00% 3.90% 3.00%
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)     $ 66.2 $ 5.5  
Employee and employer contributions     $ 2.1 $ 1.9  
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase     3.00% 2.40% 3.00%
Fair value of plan assets 225.4 $ 303.2 $ 225.4 $ 303.2 $ 297.9
Fair value of pension assets attributable to acquisitions       0.0  
Estimated Future Benefit Payments          
2023 16.4   16.4    
2024 16.5   16.5    
2025 16.8   16.8    
2026 17.0   17.0    
2027 17.0   17.0    
2028-2032 84.1   84.1    
Defined Contribution Plans          
Defined Benefit Plan, Benefit Obligation, Business Combination     $ 0.0 $ 0.0  
Defined Benefit Plan, Plan Assets, Payment for Settlement 0.0 0.0      
Foreign Plan          
Fair Value Measurements          
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate     1.10% 0.70% 0.30%
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)     $ 30.2 $ 7.0  
Employee and employer contributions     $ 9.2 $ 10.1  
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase     2.00% 2.00% 2.00%
Fair value of plan assets 41.5 47.6 $ 41.5 $ 47.6 $ 43.8
Fair value of pension assets attributable to acquisitions     0.2 0.0  
Estimated Future Benefit Payments          
2023   8.0   8.0  
2024   7.9   7.9  
2025   7.8   7.8  
2026   8.0   8.0  
2027   7.9   7.9  
2028-2032   37.2   37.2  
Defined Contribution Plans          
Defined Benefit Plan, Benefit Obligation, Business Combination     1.4 0.0  
Defined Benefit Plan, Plan Assets, Payment for Settlement     (2.8) (4.1)  
Foreign Plan | Cash equivalents | Level 1          
Fair Value Measurements          
Fair value of plan assets 4.0 4.8 4.0 4.8  
Foreign Plan | Cash equivalents | Level 2          
Fair Value Measurements          
Fair value of plan assets 0.0 0.0 0.0 0.0  
Foreign Plan | Cash equivalents | Level 3          
Fair Value Measurements          
Fair value of plan assets 0.0 0.0 0.0 0.0  
Foreign Plan | Estimate of Fair Value Measurement [Member]          
Fair Value Measurements          
Fair value of plan assets 41.5 47.6 41.5 47.6  
Foreign Plan | Estimate of Fair Value Measurement [Member] | Level 1          
Fair Value Measurements          
Fair value of plan assets 19.0 39.6 19.0 39.6  
Foreign Plan | Estimate of Fair Value Measurement [Member] | Level 2          
Fair Value Measurements          
Fair value of plan assets 18.2 3.5 18.2 3.5  
Foreign Plan | Estimate of Fair Value Measurement [Member] | Level 3          
Fair Value Measurements          
Fair value of plan assets 4.3 4.5 4.3 4.5  
Foreign Plan | Estimate of Fair Value Measurement [Member] | Cash equivalents          
Fair Value Measurements          
Fair value of plan assets 4.0 4.8 4.0 4.8  
Foreign Plan | Estimate of Fair Value Measurement [Member] | Equity securities          
Fair Value Measurements          
Fair value of plan assets 10.9 16.3 10.9 16.3  
Foreign Plan | Estimate of Fair Value Measurement [Member] | Equity securities | Level 1          
Fair Value Measurements          
Fair value of plan assets 10.9 16.3 10.9 16.3  
Foreign Plan | Estimate of Fair Value Measurement [Member] | Equity securities | Level 2          
Fair Value Measurements          
Fair value of plan assets 0.0 0.0 0.0 0.0  
Foreign Plan | Estimate of Fair Value Measurement [Member] | Equity securities | Level 3          
Fair Value Measurements          
Fair value of plan assets 0.0 0.0 0.0 0.0  
Foreign Plan | Estimate of Fair Value Measurement [Member] | Government bonds          
Fair Value Measurements          
Fair value of plan assets 4.1 4.8 4.1 4.8  
Foreign Plan | Estimate of Fair Value Measurement [Member] | Government bonds | Level 1          
Fair Value Measurements          
Fair value of plan assets 4.1 4.8 4.1 4.8  
Foreign Plan | Estimate of Fair Value Measurement [Member] | Government bonds | Level 2          
Fair Value Measurements          
Fair value of plan assets 0.0 0.0 0.0 0.0  
Foreign Plan | Estimate of Fair Value Measurement [Member] | Government bonds | Level 3          
Fair Value Measurements          
Fair value of plan assets 0.0 0.0 0.0 0.0  
Foreign Plan | Estimate of Fair Value Measurement [Member] | Corporate bonds          
Fair Value Measurements          
Fair value of plan assets 16.7 13.7 16.7 13.7  
Foreign Plan | Estimate of Fair Value Measurement [Member] | Corporate bonds | Level 1          
Fair Value Measurements          
Fair value of plan assets 0.0 13.7 0.0 13.7  
Foreign Plan | Estimate of Fair Value Measurement [Member] | Corporate bonds | Level 2          
Fair Value Measurements          
Fair value of plan assets 16.7 0.0 16.7 0.0  
Foreign Plan | Estimate of Fair Value Measurement [Member] | Corporate bonds | Level 3          
Fair Value Measurements          
Fair value of plan assets 0.0 0.0 0.0 0.0  
Foreign Plan | Estimate of Fair Value Measurement [Member] | Real estate and real estate funds          
Fair Value Measurements          
Fair value of plan assets 4.3 4.5 4.3 4.5  
Foreign Plan | Estimate of Fair Value Measurement [Member] | Real estate and real estate funds | Level 1          
Fair Value Measurements          
Fair value of plan assets 0.0 0.0 0.0 0.0  
Foreign Plan | Estimate of Fair Value Measurement [Member] | Real estate and real estate funds | Level 2          
Fair Value Measurements          
Fair value of plan assets 0.0 0.0 0.0 0.0  
Foreign Plan | Estimate of Fair Value Measurement [Member] | Real estate and real estate funds | Level 3          
Fair Value Measurements          
Fair value of plan assets 4.3 4.5 4.3 4.5  
Foreign Plan | Estimate of Fair Value Measurement [Member] | Other          
Fair Value Measurements          
Fair value of plan assets 1.5 3.5 1.5 3.5  
Foreign Plan | Estimate of Fair Value Measurement [Member] | Other | Level 1          
Fair Value Measurements          
Fair value of plan assets 0.0 0.0 0.0 0.0  
Foreign Plan | Estimate of Fair Value Measurement [Member] | Other | Level 2          
Fair Value Measurements          
Fair value of plan assets 1.5 3.5 1.5 3.5  
Foreign Plan | Estimate of Fair Value Measurement [Member] | Other | Level 3          
Fair Value Measurements          
Fair value of plan assets $ 0.0 $ 0.0 $ 0.0 $ 0.0