Annual report pursuant to Section 13 and 15(d)

Retirement Benefits (Details)

v3.10.0.1
Retirement Benefits (Details)
$ in Millions
12 Months Ended
Sep. 30, 2018
USD ($)
program
shares
Sep. 30, 2017
USD ($)
Sep. 30, 2016
USD ($)
Retirement and Postemployment Benefits      
Percentage of employee participation in the defined benefit retirement programs 38.00%    
Number of defined benefit retirement programs in which a specified percentage of employees participate | program 1    
Number of defined benefit retirement programs | program 4    
Funded status:      
Plan assets less than benefit obligations   $ (102.0)  
Amounts recorded in the consolidated balance sheets:      
Accrued pension costs, long-term portion $ 120.5 129.6  
Plan Assets      
Reporting entity's common stock owned by trust (in shares) | shares 0    
Domestic Plan [Member]      
Defined benefit plans      
Service cost $ 2.7 3.6 $ 3.9
Interest cost 8.7 8.8 9.5
Expected return on plan assets (14.0) (13.7) (9.7)
Amortization of unrecognized prior service cost, net (0.2) (0.4) (0.6)
Amortization of actuarial loss 3.2 3.6 3.8
Settlement expense 0.0 0.1 0.0
Net pension costs (0.8) (2.8) (8.1)
Change in benefit obligation:      
Projected benefit obligation at beginning of year 281.8 294.2  
Service cost 2.7 3.6 3.9
Interest cost 8.7 8.8 9.5
Actuarial loss (gain) (14.7) (6.9)  
Benefits paid (11.5) (11.0)  
Gain due to settlement 0.0 (6.9)  
Employee contributions 0.0 0.0  
Effect of exchange rates on projected benefit obligation 0.0 0.0  
Projected benefit obligation at end of year 267.0 281.8 294.2
Change in plan assets:      
Fair value of plan assets at beginning of year 262.4 173.7  
Actual return on plan assets 0.6 17.9  
Employee and employer contributions 1.8 81.8  
Defined Benefit Plan, Plan Assets, Benefits Paid 11.5 11.0  
Effect of exchange rates on plan assets 0.0 0.0  
Fair value of plan assets at end of year 253.3 262.4 $ 173.7
Funded status:      
Plan assets less than benefit obligations (13.7) (19.4)  
Amounts recorded in the consolidated balance sheets:      
Assets for Plan Benefits, Defined Benefit Plan 12.0 8.2  
Accrued pension costs, current portion (2.0) (1.8)  
Accrued pension costs, long-term portion 23.7 25.8  
Plan assets less than benefit obligations (13.7) (19.4)  
Accumulated Benefit Obligation      
Projected benefit obligation 25.7 27.7  
Accumulated benefit obligation 25.7 27.6  
Fair value of plan assets $ 0.0 $ 0.0  
Actuarial Assumptions      
Discount rate for obligation, end of year (as a percent) 4.20% 3.70% 3.60%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate 3.40% 3.50% 4.40%
Expected rate of return on plan assets (as a percent) 5.60% 5.60% 5.50%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase 3.00% 3.00% 3.00%
Foreign Plan [Member]      
Defined benefit plans      
Service cost $ 1.4 $ 1.3 $ 1.8
Interest cost 1.1 0.7 1.8
Expected return on plan assets (0.6) (0.5) (1.0)
Amortization of unrecognized prior service cost, net 0.1 0.1 0.1
Amortization of actuarial loss 0.7 1.1 0.3
Settlement expense 0.0 0.6 0.5
Net pension costs 2.7 3.3 3.5
Change in benefit obligation:      
Projected benefit obligation at beginning of year 133.4 140.9  
Service cost 1.4 1.3 1.8
Interest cost 1.1 0.7 1.8
Actuarial loss (gain) 0.4 (9.5)  
Benefits paid (5.2) (5.7)  
Gain due to settlement (3.4) (1.2)  
Employee contributions 0.9 0.8  
Effect of exchange rates on projected benefit obligation (2.3) 6.1  
Projected benefit obligation at end of year 126.3 133.4 140.9
Change in plan assets:      
Fair value of plan assets at beginning of year 31.4 29.7  
Actual return on plan assets (0.1) 0.3  
Employee and employer contributions 9.0 8.5  
Defined Benefit Plan, Plan Assets, Benefits Paid 5.2 5.7  
Effect of exchange rates on plan assets (0.2) 0.2  
Fair value of plan assets at end of year 31.9 31.4 $ 29.7
Funded status:      
Plan assets less than benefit obligations (94.4)    
Amounts recorded in the consolidated balance sheets:      
Assets for Plan Benefits, Defined Benefit Plan 2.2 0.4  
Accrued pension costs, current portion (6.6) (6.8)  
Accrued pension costs, long-term portion 90.0 95.6  
Plan assets less than benefit obligations (94.4) (102.0)  
Accumulated Benefit Obligation      
Projected benefit obligation 96.6 102.0  
Accumulated benefit obligation 96.6 102.0  
Fair value of plan assets $ 0.0 $ 0.0  
Actuarial Assumptions      
Discount rate for obligation, end of year (as a percent) 1.20% 1.10% 1.00%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate 1.50% 0.50% 1.70%
Expected rate of return on plan assets (as a percent) 2.00% 2.00% 2.00%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase 2.00% 2.00% 2.00%
Other Postretirement Benefits Plan [Member]      
Retirement and Postemployment Benefits      
Defined Benefit Plan, Effect of One Percentage Point Increase on Accumulated Postretirement Benefit Obligation $ 0.5    
Defined benefit plans      
Service cost 0.3 $ 0.4  
Interest cost 0.2 0.2  
Change in benefit obligation:      
Projected benefit obligation at beginning of year 9.0 10.3  
Service cost 0.3 0.4  
Interest cost 0.2 0.2  
Actuarial loss (gain) 0.9 0.9  
Benefits paid (1.0) (1.0)  
Projected benefit obligation at end of year 7.6 9.0 $ 10.3
Amounts recorded in the consolidated balance sheets:      
Accrued pension costs, current portion (0.8) (0.8)  
Accrued pension costs, long-term portion 6.8 8.2  
Accumulated other comprehensive loss      
Net actuarial gains (losses) 4.0 3.4  
Prior service cost 0.7 0.8  
Aggregate tax effect 1.7 $ 1.6  
Amount that will be amortized from accumulated other comprehensive loss into net benefit costs $ 0.5    
Actuarial Assumptions      
Discount rate for obligation, end of year (as a percent) 4.00% 3.30% 3.10%
Pension Plans Defined Benefit      
Accumulated other comprehensive loss      
Net actuarial gains (losses) $ (67.2) $ 71.9  
Prior service cost 0.8 (1.0)  
Aggregate tax effect (24.0) (25.0)  
Amount that will be amortized from accumulated other comprehensive loss into net benefit costs 2.0    
Accumulated Benefit Obligation      
Accumulated benefit obligation $ 387.0 $ 407.7