Revenue Recognition - Disaggregation of Revenue by Operating Segment and by Geographic Region (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
North America
Disaggregation of Revenue [Line Items]
Sales	826.0	1,008.0	2,855.0	2,993.9
Europe, Middle East and Africa (EMEA)
Disaggregation of Revenue [Line Items]
Sales	280.4	307.9	924.1	933.4
Asia Pacific
Disaggregation of Revenue [Line Items]
Sales	206.9	232.7	637.3	661.8
Latin America
Disaggregation of Revenue [Line Items]
Sales	80.7	116.5	343.4	375.5
Architecture & Software
Disaggregation of Revenue [Line Items]
Sales	621.4	747.9	2,130.1	2,240.7
Architecture & Software | North America
Disaggregation of Revenue [Line Items]
Sales	348.6	437.1	1,236.6	1,303.0
Architecture & Software | Europe, Middle East and Africa (EMEA)
Disaggregation of Revenue [Line Items]
Sales	145.7	162.0	456.9	493.5
Architecture & Software | Asia Pacific
Disaggregation of Revenue [Line Items]
Sales	101.9	107.7	312.1	306.8
Architecture & Software | Latin America
Disaggregation of Revenue [Line Items]
Sales	25.2	41.1	124.5	137.4
Control Products & Solutions
Disaggregation of Revenue [Line Items]
Sales	772.6	917.2	2,629.7	2,723.9
Control Products & Solutions | North America
Disaggregation of Revenue [Line Items]
Sales	477.4	570.9	1,618.4	1,690.9
Control Products & Solutions | Europe, Middle East and Africa (EMEA)
Disaggregation of Revenue [Line Items]
Sales	134.7	145.9	467.2	439.9
Control Products & Solutions | Asia Pacific
Disaggregation of Revenue [Line Items]
Sales	105.0	125.0	325.2	355.0
Control Products & Solutions | Latin America
Disaggregation of Revenue [Line Items]
Sales	$ 55.5	$ 75.4	$ 218.9	$ 238.1