Revenue Recognition (Disaggregation of Revenue) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Disaggregation of Revenue [Line Items]
Sales	$ 12,698.6	$ 10,323.0	$ 8,856.3
Operating Segments
Disaggregation of Revenue [Line Items]
Sales	$ 12,698.6	$ 10,323.0	$ 8,856.3
Percent sales by supply mode	100.00%	100.00%	100.00%
Americas | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	$ 5,368.9	$ 4,167.6	$ 3,630.7
Asia | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	3,143.3	2,920.8	2,716.5
Europe | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	3,086.1	2,345.6	1,847.0
Middle East and India | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	129.5	99.3	79.3
Corporate and other | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	970.8	789.7	582.8
On-site | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	$ 6,633.1	$ 5,061.4	$ 4,322.3
Percent sales by supply mode	52.00%	49.00%	49.00%
On-site | Americas | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	$ 3,423.1	$ 2,469.5	$ 2,040.2
On-site | Asia | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	1,833.9	1,718.8	1,652.8
On-site | Europe | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	1,298.2	802.4	574.6
On-site | Middle East and India | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	77.9	70.7	54.7
On-site | Corporate and other | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	0.0	0.0	0.0
Merchant | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	$ 5,094.7	$ 4,471.9	$ 3,951.2
Percent sales by supply mode	40.00%	43.00%	45.00%
Merchant | Americas | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	$ 1,945.8	$ 1,698.1	$ 1,590.5
Merchant | Asia | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	1,309.4	1,202.0	1,063.7
Merchant | Europe | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	1,787.9	1,543.2	1,272.4
Merchant | Middle East and India | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	51.6	28.6	24.6
Merchant | Corporate and other | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	0.0	0.0	0.0
Sale of Equipment | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	$ 970.8	$ 789.7	$ 582.8
Percent sales by supply mode	8.00%	8.00%	6.00%
Sale of Equipment | Americas | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	$ 0.0	$ 0.0	$ 0.0
Sale of Equipment | Asia | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	0.0	0.0	0.0
Sale of Equipment | Europe | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	0.0	0.0	0.0
Sale of Equipment | Middle East and India | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	0.0	0.0	0.0
Sale of Equipment | Corporate and other | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	$ 970.8	$ 789.7	$ 582.8