Business Segment Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012
Sales and operating results of reportable segments
Sales	$ 1,781.8	$ 1,649.5	$ 1,600.5	$ 1,591.7	$ 1,715.7	$ 1,624.2	$ 1,522.8	$ 1,489.2	$ 6,623.5	$ 6,351.9	$ 6,259.4
Income before income taxes	339.0	274.0	248.4	272.8	279.2	257.4	227.1	217.2	1,134.2	980.9	965.9
Purchase accounting depreciation and amortization									(21.6)	(19.3)	(19.8)
Interest expense									(59.3)	(60.9)	(60.1)
Operating Segments [Member]
Sales and operating results of reportable segments
Income before income taxes									1,352.0	1,236.8	1,163.9
Architecture and Software [Member]
Sales and operating results of reportable segments
Sales									2,845.3	2,682.0	2,650.4
Income before income taxes									839.6	759.4	714.4
Control Products and Solutions [Member]
Sales and operating results of reportable segments
Sales									3,778.2	3,669.9	3,609.0
Income before income taxes									512.4	477.4	449.5
Segment Reconciling Items [Member]
Sales and operating results of reportable segments
Purchase accounting depreciation and amortization									(21.6)	(19.3)	(19.8)
Non-operating pension cost									(55.9)	(78.5)	(35.2)
Corporate, Non-Segment [Member]
Sales and operating results of reportable segments
General corporate-net									(81.0)	(97.2)	(82.9)
Interest expense									$ (59.3)	$ (60.9)	$ (60.1)