Annual report pursuant to Section 13 and 15(d)

Income taxes - Narrative (Details)

v3.5.0.2
Income taxes - Narrative (Details) - USD ($)
$ in Millions
12 Months Ended
Sep. 30, 2016
Sep. 30, 2015
Sep. 30, 2014
Net operating loss carryforwards      
Cumulative earnings from foreign subsidiaries $ 218.0    
Income taxes paid 108.3 $ 81.3 $ 79.4
Unrecognized tax benefits      
Net unrecognized tax benefits 1.1 1.0  
Unrecognized tax benefits that, if recognized, would affect the annual effective income tax rate 1.1 1.0  
Interest and penalties included in net liability balance 0.6 0.6  
Maximum      
Unrecognized tax benefits      
Interest expense recognized related to unrecognized tax benefits $ 0.1 $ 0.1 $ 0.1