Business Segment Information (Reconciliation of Operating Income) (Details) (USD $)
In Millions, unless otherwise specified
3 Months Ended 6 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Mar. 31, 2015
Mar. 31, 2014
Segment Reporting Information [Line Items]        
Business restructuring and cost reduction actions $ (55.4) $ 0 $ (87.8) $ 0
Pension settlement loss (12.6) 0 (12.6) 0
Gain on previously held equity interest 0 0 17.9 0
Operating Income 374.4 384.7 804.4 770.3
Segment Total [Member]        
Segment Reporting Information [Line Items]        
Operating Income $ 442.4 $ 384.7 $ 886.9 $ 770.3