Business Segment Information (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Sales and operating results of reportable segments
Sales	$ 1,607.5	$ 1,575.2	$ 1,550.8	$ 1,574.4	$ 1,781.8	$ 1,649.5	$ 1,600.5	$ 1,591.7	$ 6,307.9	$ 6,623.5	$ 6,351.9
Income before income taxes	$ 278.9	$ 284.6	$ 276.5	$ 287.5	$ 339.0	$ 274.0	$ 248.4	$ 272.8	1,127.5	1,134.2	980.9
Purchase accounting depreciation and amortization									(21.0)	(21.6)	(19.3)
Interest expense									(63.7)	(59.3)	(60.9)
Operating Segments [Member]
Sales and operating results of reportable segments
Income before income taxes									1,360.5	1,352.0	1,236.8
Architecture and Software [Member]
Sales and operating results of reportable segments
Sales									2,749.5	2,845.3	2,682.0
Income before income taxes									808.6	839.6	759.4
Control Products and Solutions [Member]
Sales and operating results of reportable segments
Sales									3,558.4	3,778.2	3,669.9
Income before income taxes									551.9	512.4	477.4
Segment Reconciling Items [Member]
Sales and operating results of reportable segments
Purchase accounting depreciation and amortization									(21.0)	(21.6)	(19.3)
Non-operating pension cost									(62.7)	(55.9)	(78.5)
Corporate, Non-Segment [Member]
Sales and operating results of reportable segments
General corporate-net									$ (85.6)	$ (81.0)	$ (97.2)