Quarterly Financial Information (Unaudited) (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
Quarterly Financial Information (Unaudited)
Sales	$ 1,664.0	$ 1,560.4	$ 1,561.1	$ 1,473.9	$ 1,654.3	$ 1,516.2	$ 1,464.1	$ 1,365.8	$ 6,259.4	$ 6,000.4	$ 4,857.0
Gross profit	654.2	631.5	618.3	618.7	663.2	606.8	576.5	543.9	2,522.7	2,390.4	1,936.4
Income from continuing operations before income taxes	254.9	244.8	223.3	242.9	256.1	221.2	203.6	186.7	965.9	867.6	544.2
Income from continuing operations					201.8	178.8	166.4	150.1	737.0	697.1	440.4
Income from discontinued operations (Note 13)					0	0.7	0	0	0	0.7	23.9
Net income	$ 195.2	$ 190.7	$ 167.8	$ 183.3	$ 201.8	$ 179.5	$ 166.4	$ 150.1	$ 737.0	$ 697.8	$ 464.3
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