Annual report pursuant to Section 13 and 15(d)

Summary of Significant Accounting Policies - Intangible assets (Details)

v3.8.0.1
Summary of Significant Accounting Policies - Intangible assets (Details) - USD ($)
$ in Millions
12 Months Ended
Sep. 30, 2017
Sep. 30, 2016
Sep. 30, 2015
Future amortization expense      
2017 $ 32.2    
2018 32.0    
2019 31.4    
2020 30.4    
2021 29.3    
Components of intangible assets and the related accumulated amortization      
Impairment of Intangible Assets, Indefinite-lived (Excluding Goodwill) 0.0 $ 2.2 $ 0.0
Cost 598.1 585.4  
Accumulated amortization (207.6) (174.2)  
Other Finite-Lived Intangible Assets, Gross $ 731.5 715.7  
Minimum      
Components of intangible assets and the related accumulated amortization      
Intangible assets amortization period 3 years    
Maximum      
Components of intangible assets and the related accumulated amortization      
Intangible assets amortization period 21 years    
Trade names      
Components of intangible assets and the related accumulated amortization      
Trade names, indefinite lives $ 133.4 130.3  
Trade names      
Components of intangible assets and the related accumulated amortization      
Cost 0.2 0.2  
Accumulated amortization (0.1) (0.1)  
Customer relationships      
Components of intangible assets and the related accumulated amortization      
Cost 468.7 459.5  
Accumulated amortization (125.9) (100.7)  
Technology, including patents      
Components of intangible assets and the related accumulated amortization      
Cost 80.7 77.9  
Accumulated amortization (39.9) (33.3)  
Software      
Components of intangible assets and the related accumulated amortization      
Cost 48.3 47.4  
Accumulated amortization (41.5) (39.8)  
Other      
Components of intangible assets and the related accumulated amortization      
Cost 0.2 0.4  
Accumulated amortization (0.2) $ (0.3)  
Customer Concentration Risk [Member] | Trade names      
Components of intangible assets and the related accumulated amortization      
Trade names, indefinite lives $ 13.0