Business Segment Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2013	Mar. 31, 2012
Sales and operating results of reportable segments
Sales	$ 1,522.8	$ 1,561.1	$ 3,012.0	$ 3,035.0
Income before taxes	227.1	223.3	444.3	466.2
Total Segments [Member]
Sales and operating results of reportable segments
Income before taxes	285.2	276.5	561.2	568.4
Architecture and Software [Member]
Sales and operating results of reportable segments
Sales	639.2	664.8	1,296.7	1,315.3
Income before taxes	169.9	170.6	353.1	359.8
Control Products and Solutions [Member]
Sales and operating results of reportable segments
Sales	883.6	896.3	1,715.3	1,719.7
Income before taxes	115.3	105.9	208.1	208.6
Purchase accounting depreciation and amortization [Member]
Sales and operating results of reportable segments
Income before taxes	(5.0)	(4.9)	(10.2)	(9.9)
General corporate - net [Member]
Sales and operating results of reportable segments
Income before taxes	(18.1)	(24.5)	(36.6)	(44.7)
Non-operating pension cost [Member]
Sales and operating results of reportable segments
Income before taxes	(19.7)	(8.8)	(39.4)	(17.6)
Interest expense [Member]
Sales and operating results of reportable segments
Income before taxes	$ (15.3)	$ (15.0)	$ (30.7)	$ (30.0)