Annual report pursuant to Section 13 and 15(d)

Retirement Benefits (Details 3)

v2.4.0.8
Retirement Benefits (Details 3) (Other Postretirement Benefit Plans Defined Benefit [Member], USD $)
In Millions, unless otherwise specified
12 Months Ended
Sep. 30, 2014
Sep. 30, 2013
Sep. 30, 2012
Other Postretirement Benefit Plans Defined Benefit [Member]
     
Retirement and Postemployment Benefits      
Postretirement healthcare benefit cost $ 0.5 $ 0.6 $ 1.0
Weighted average assumptions used in revaluing obligation under the postretirement healthcare plan      
Discount rate for obligation, end of year (as a percent) 3.70% 3.50% 3.40%
Healthcare cost rate assumed for next year (as a percent) 7.20% 7.70% 7.90%
Ultimate trend rate (as a percent) 5.00% 5.00% 5.00%
One-percentage-point increase/decrease in the assumed healthcare cost trend rates      
Impact of a one percentage point increase in healthcare cost trends on service and interest costs 0.1    
Impact of a one percentage point decrease in healthcare cost trends on service and interest costs 0.1    
Impact of a one percentage point increase in healthcare cost trends on the benefit obligation 0.7    
Impact of a one percentage point decrease in healthcare cost trends on the benefit obligation 0.7    
Employer's expected annual future contribution to the postretirement healthcare plan $ 0.8