Revenue Recognition (Disaggregation of Revenue) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Disaggregation of Revenue [Line Items]
Sales	$ 12,037.3	$ 12,100.6	$ 12,600.0
Operating Segments
Disaggregation of Revenue [Line Items]
Sales	$ 12,037.3	$ 12,100.6	$ 12,600.0
Percent sales by supply mode	100.00%	100.00%	100.00%
Americas | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	$ 5,125.9	$ 5,040.1	$ 5,369.3
Asia | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	3,271.0	3,224.3	3,216.1
Europe | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	2,984.5	2,823.4	2,963.1
Middle East and India | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	135.9	134.4	162.5
Corporate and other | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	520.0	878.4	889.0
On-site | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	$ 6,180.4	$ 5,892.7	$ 6,179.2
Percent sales by supply mode	52.00%	49.00%	49.00%
On-site | Americas | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	$ 2,918.2	$ 2,844.4	$ 3,143.9
On-site | Asia | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	2,190.9	2,066.4	1,923.0
On-site | Europe | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	992.7	910.5	1,036.6
On-site | Middle East and India | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	78.6	71.4	75.7
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	$ 5,336.9	$ 5,329.5	$ 5,531.8
Percent sales by supply mode	44.00%	44.00%	44.00%
Merchant | Americas | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	$ 2,207.7	$ 2,195.7	$ 2,225.4
Merchant | Asia | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	1,080.1	1,157.9	1,293.1
Merchant | Europe | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	1,991.8	1,912.9	1,926.5
Merchant | Middle East and India | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	57.3	63.0	86.8
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	$ 520.0	$ 878.4	$ 889.0
Percent sales by supply mode	4.00%	7.00%	7.00%
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	$ 520.0	$ 878.4	$ 889.0
Financing and Lease Arrangement | Revenue Benchmark | Revenue Source Concentration Risk
Disaggregation of Revenue [Line Items]
Interest income associated with financing and lease arrangements as a percentage of total consolidated sales	1.00%	1.00%	1.00%