Revenue Recognition - Disaggregation of Revenue by Operating Segment and Major Types of Products or Services (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Disaggregation of Revenue [Line Items]
Sales	$ 1,394.0	$ 1,665.1	$ 4,759.8	$ 4,964.6
Products
Disaggregation of Revenue [Line Items]
Sales	927.6	1,105.2	3,203.9	3,343.3
Solutions & Services
Disaggregation of Revenue [Line Items]
Sales	466.4	559.9	1,555.9	1,621.3
Architecture & Software
Disaggregation of Revenue [Line Items]
Sales	621.4	747.9	2,130.1	2,240.7
Architecture & Software | Products
Disaggregation of Revenue [Line Items]
Sales	621.4	747.9	2,130.1	2,240.7
Architecture & Software | Solutions & Services
Disaggregation of Revenue [Line Items]
Sales	0.0	0.0	0.0	0.0
Control Products & Solutions
Disaggregation of Revenue [Line Items]
Sales	772.6	917.2	2,629.7	2,723.9
Control Products & Solutions | Products
Disaggregation of Revenue [Line Items]
Sales	306.2	357.3	1,073.8	1,102.6
Control Products & Solutions | Solutions & Services
Disaggregation of Revenue [Line Items]
Sales	$ 466.4	$ 559.9	$ 1,555.9	$ 1,621.3