Basis of Presentation and Accounting Policies (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010
Reconciled Basic and Diluted EPS
Income from continuing operations					$ 201.8	$ 178.8	$ 166.4	$ 150.1	$ 737.0	$ 697.1	$ 440.4
Less: Allocation to participating securities									(1.4)	(1.4)	(1.0)
Income from continuing operations available to common shareowners									735.6	695.7	439.4
Income from discontinued operations (Note 13)					0	0.7	0	0	0	0.7	23.9
Less: Allocation to participating securities									0	0	(0.1)
Income from discontinued operations available to common shareowners									0	0.7	23.8
Net income	195.2	190.7	167.8	183.3	201.8	179.5	166.4	150.1	737.0	697.8	464.3
Less: Allocation to participating securities									(1.4)	(1.4)	(1.1)
Net income available to common shareowners									$ 735.6	$ 696.4	$ 463.2
Basic weighted average outstanding shares									141.5	142.7	142.0
Effect of dilutive securities
Stock options									1.6	2.1	1.7
Performance shares									0.3	0.4	0.3
Diluted weighted average outstanding shares									143.4	145.2	144.0
Basic earnings per share:
Continuing operations	$ 1.39	$ 1.34	$ 1.18	$ 1.29	$ 1.41	$ 1.24	$ 1.16	$ 1.06	$ 5.20	$ 4.88	$ 3.09
Discontinued operations					$ 0.00	$ 0.01	$ 0.00	$ 0.00	$ 0.00	$ 0.00	$ 0.17
Net income					$ 1.41	$ 1.25	$ 1.16	$ 1.06	$ 5.20	$ 4.88	$ 3.26
Diluted earnings per share:
Continuing operations	$ 1.38	$ 1.33	$ 1.16	$ 1.27	$ 1.39	$ 1.22	$ 1.14	$ 1.04	$ 5.13	$ 4.79	$ 3.05
Discontinued operations					$ 0.00	$ 0.01	$ 0.00	$ 0.00	$ 0.00	$ 0.01	$ 0.17
Net income					$ 1.39	$ 1.23	$ 1.14	$ 1.04	$ 5.13	$ 4.80	$ 3.22