Business Segment Information (Details) (USD $) In Millions, 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
Sales and operating results of reportable segments
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
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
Total Segments [Member]
Sales and operating results of reportable segments
Income from continuing operations before income taxes									1,131.4	1,027.6	717.2
Architecture and Software [Member]
Sales and operating results of reportable segments
Sales									2,650.4	2,594.3	2,115.0
Income from continuing operations before income taxes									702.8	659.1	475.4
Control Products and Solutions [Member]
Sales and operating results of reportable segments
Sales									3,609.0	3,406.1	2,742.0
Income from continuing operations before income taxes									428.6	368.5	241.8
Purchase accounting depreciation and amortization [Member]
Sales and operating results of reportable segments
Income from continuing operations before income taxes									(19.8)	(19.8)	(18.9)
General corporate - net [Member]
Sales and operating results of reportable segments
Income from continuing operations before income taxes									(85.6)	(80.7)	(93.6)
Interest expense [Member]
Sales and operating results of reportable segments
Income from continuing operations before income taxes									$ (60.1)	$ (59.5)	$ (60.5)