Revenue Recognition - Disaggregation of Revenue by Operating Segment and by Geographic Region (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020	Mar. 31, 2019
Disaggregation of Revenue [Line Items]
Sales	$ 1,681.3	$ 1,657.2	$ 3,365.8	$ 3,299.5
North America
Disaggregation of Revenue [Line Items]
Sales	1,022.1	987.1	2,029.0	1,985.9
Europe, Middle East and Africa (EMEA)
Disaggregation of Revenue [Line Items]
Sales	333.6	331.1	643.7	625.5
Asia Pacific
Disaggregation of Revenue [Line Items]
Sales	200.8	214.7	430.4	429.1
Latin America
Disaggregation of Revenue [Line Items]
Sales	124.8	124.3	262.7	259.0
Architecture & Software
Disaggregation of Revenue [Line Items]
Sales	757.1	739.7	1,508.7	1,492.8
Architecture & Software | North America
Disaggregation of Revenue [Line Items]
Sales	447.9	423.1	888.1	865.9
Architecture & Software | Europe, Middle East and Africa (EMEA)
Disaggregation of Revenue [Line Items]
Sales	162.3	176.0	311.2	331.5
Architecture & Software | Asia Pacific
Disaggregation of Revenue [Line Items]
Sales	98.8	97.8	210.2	199.1
Architecture & Software | Latin America
Disaggregation of Revenue [Line Items]
Sales	48.1	42.8	99.2	96.3
Control Products & Solutions
Disaggregation of Revenue [Line Items]
Sales	924.2	917.5	1,857.1	1,806.7
Control Products & Solutions | North America
Disaggregation of Revenue [Line Items]
Sales	574.2	564.0	1,140.9	1,120.0
Control Products & Solutions | Europe, Middle East and Africa (EMEA)
Disaggregation of Revenue [Line Items]
Sales	171.3	155.1	332.5	294.0
Control Products & Solutions | Asia Pacific
Disaggregation of Revenue [Line Items]
Sales	102.0	116.9	220.2	230.0
Control Products & Solutions | Latin America
Disaggregation of Revenue [Line Items]
Sales	$ 76.7	$ 81.5	$ 163.5	$ 162.7