Revenue Recognition (Disaggregation of Revenue) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Disaggregation of Revenue [Line Items]
Sales	$ 2,985.5	$ 3,033.9	$ 8,913.1	$ 9,408.7
Operating Segments
Disaggregation of Revenue [Line Items]
Sales	$ 2,985.5	$ 3,033.9	$ 8,913.1	$ 9,408.7
Percent sales by supply mode	100.00%	100.00%	100.00%	100.00%
Americas | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	$ 1,234.7	$ 1,260.7	$ 3,732.6	$ 4,018.0
Asia | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	789.6	822.9	2,363.1	2,414.6
Europe | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	693.4	706.6	2,092.5	2,251.4
Middle East and India | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	32.8	39.7	103.9	125.9
Corporate and other | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	235.0	204.0	621.0	598.8
On-site | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	$ 1,423.9	$ 1,438.3	$ 4,322.3	$ 4,663.1
Percent sales by supply mode	48.00%	47.00%	48.00%	50.00%
On-site | Americas | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	$ 680.3	$ 704.1	$ 2,089.9	$ 2,351.8
On-site | Asia | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	506.9	496.8	1,506.0	1,444.8
On-site | Europe | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	218.3	220.5	672.0	808.0
On-site | Middle East and India | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	18.4	16.9	54.4	58.5
On-site | Corporate and other | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	0.0	0.0	0.0	0.0
Merchant | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	$ 1,326.6	$ 1,391.6	$ 3,969.8	$ 4,146.8
Percent sales by supply mode	44.00%	46.00%	45.00%	44.00%
Merchant | Americas | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	$ 554.4	$ 556.6	$ 1,642.7	$ 1,666.2
Merchant | Asia | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	282.7	326.1	857.1	969.8
Merchant | Europe | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	475.1	486.1	1,420.5	1,443.4
Merchant | Middle East and India | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	14.4	22.8	49.5	67.4
Merchant | Corporate and other | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	0.0	0.0	0.0	0.0
Sale of Equipment | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	$ 235.0	$ 204.0	$ 621.0	$ 598.8
Percent sales by supply mode	8.00%	7.00%	7.00%	6.00%
Sale of Equipment | Americas | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	$ 0.0	$ 0.0	$ 0.0	$ 0.0
Sale of Equipment | Asia | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	0.0	0.0	0.0	0.0
Sale of Equipment | Europe | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	0.0	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	0.0
Sale of Equipment | Corporate and other | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	$ 235.0	$ 204.0	$ 621.0	$ 598.8
Financing And Lease Arrangment | Revenue Benchmark | Revenue Source Concentration Risk
Disaggregation of Revenue [Line Items]
Concentration risk (in percent)	2.00%		1.00%