Business Segment Information - Sales and Operating Results (Details) - USD ($) $ in Millions	3 Months Ended
Dec. 31, 2020	Dec. 31, 2019
Sales and operating results of reportable segments
Sales	$ 1,565.3	$ 1,684.5
Purchase accounting depreciation and amortization	(11.7)	(10.0)
Corporate and other	(28.0)	(32.8)
Non-operating pension and postretirement benefit cost	(7.0)	(8.7)
Gain on investments	390.4	71.0
Legal Settlement	70.0	0.0
Interest (expense) income - net	(22.3)	(24.0)
Income before income taxes	700.7	334.6
Operating Segments
Sales and operating results of reportable segments
Sales	1,565.3	1,684.5
Segment operating earnings	309.3	339.1
Intelligent Devices
Sales and operating results of reportable segments
Sales	721.7	776.6
Intelligent Devices \| Operating Segments
Sales and operating results of reportable segments
Sales	721.7	776.6
Segment operating earnings	140.2	160.6
Software & Control
Sales and operating results of reportable segments
Sales	441.0	452.5
Software & Control \| Operating Segments
Sales and operating results of reportable segments
Sales	441.0	452.5
Segment operating earnings	133.1	140.4
Lifecycle Services
Sales and operating results of reportable segments
Sales	402.6	455.4
Lifecycle Services \| Operating Segments
Sales and operating results of reportable segments
Sales	402.6	455.4
Segment operating earnings	$ 36.0	$ 38.1

Equity Securities, FV-NI, Unrealized Gain (Loss), Loss On Investment

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Non-operating pension costs consist of defined benefit plan interest cost, expected return on plan assets, amortization of actuarial gains and losses and the impacts of any plan curtailments or settlements. These costs are excluded from segment operating earnings.

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