Basis of Presentation and Accounting Policies (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Reconciled Basic and Diluted EPS
Net income	$ 206.1	$ 199.7	$ 626.3	$ 578.1
Less: Allocation to participating securities	(0.3)	(0.3)	(0.5)	(0.8)
Net income available to common shareowners	$ 205.8	$ 199.4	$ 625.8	$ 577.3
Basic weighted average outstanding shares	134.3	138.0	134.9	138.3
Effect of dilutive securities
Stock options	1.1	1.4	1.1	1.5
Performance shares	0.1	0.2	0.1	0.2
Diluted weighted average outstanding shares	135.5	139.6	136.1	140.0
Earnings Per Share, Basic [Abstract]
Basic	$ 1.53	$ 1.44	$ 4.64	$ 4.17
Earnings Per Share, Diluted [Abstract]
Diluted	$ 1.52	$ 1.43	$ 4.60	$ 4.12