Revenue Recognition - Disaggregation of Revenue by Operating Segment and by Geographic Region (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Disaggregation of Revenue [Line Items]
Sales	$ 1,665.1	$ 1,698.7	$ 4,964.6	$ 4,936.5
North America
Disaggregation of Revenue [Line Items]
Sales	1,008.0		2,993.9
Europe, Middle East and Africa (EMEA)
Disaggregation of Revenue [Line Items]
Sales	307.9		933.4
Asia Pacific
Disaggregation of Revenue [Line Items]
Sales	232.7		661.8
Latin America
Disaggregation of Revenue [Line Items]
Sales	116.5		375.5
Architecture & Software
Disaggregation of Revenue [Line Items]
Sales	747.9		2,240.7
Architecture & Software | North America
Disaggregation of Revenue [Line Items]
Sales	437.1		1,303.0
Architecture & Software | Europe, Middle East and Africa (EMEA)
Disaggregation of Revenue [Line Items]
Sales	162.0		493.5
Architecture & Software | Asia Pacific
Disaggregation of Revenue [Line Items]
Sales	107.7		306.8
Architecture & Software | Latin America
Disaggregation of Revenue [Line Items]
Sales	41.1		137.4
Control Products & Solutions
Disaggregation of Revenue [Line Items]
Sales	917.2		2,723.9
Control Products & Solutions | North America
Disaggregation of Revenue [Line Items]
Sales	570.9		1,690.9
Control Products & Solutions | Europe, Middle East and Africa (EMEA)
Disaggregation of Revenue [Line Items]
Sales	145.9		439.9
Control Products & Solutions | Asia Pacific
Disaggregation of Revenue [Line Items]
Sales	125.0		355.0
Control Products & Solutions | Latin America
Disaggregation of Revenue [Line Items]
Sales	$ 75.4		$ 238.1