Supplemental Information (Other Income Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Other Income (Expense) [Abstract]
Technology and royalty income	$ 25.0	$ 26.8	$ 23.4
Interest income	4.6	9.4	6.4
Foreign exchange	(22.3)	(7.7)	(3.2)
Sale of assets and investments	37.1	9.7	20.0
Government grants	1.0	1.1	6.8
Other	1.9	13.5	16.8
Total Other Income (Expense), net	$ 47.3	$ 52.8	$ 70.2