Revenue Recognition (Disaggregation of Revenue) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2026	Mar. 31, 2025	Mar. 31, 2026	Mar. 31, 2025
Disaggregation of Revenue [Line Items]
Sales	$ 3,171.8	$ 2,916.2	$ 6,274.3	$ 5,847.7
Operating Segments
Disaggregation of Revenue [Line Items]
Sales	$ 3,171.8	$ 2,916.2	$ 6,274.3	$ 5,847.7
Percent sales by supply mode	100.00%	100.00%	100.00%	100.00%
Americas | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	$ 1,383.9	$ 1,287.2	$ 2,725.6	$ 2,574.8
Asia | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	832.6	774.1	1,664.1	1,591.2
Europe | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	789.0	727.4	1,571.0	1,424.6
Middle East and India | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	29.2	32.8	59.5	65.6
Corporate and other | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	137.1	94.7	254.1	191.5
On-site | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	$ 1,711.7	$ 1,552.5	$ 3,345.6	$ 3,040.8
Percent sales by supply mode	54.00%	53.00%	53.00%	52.00%
On-site | Americas | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	$ 840.4	$ 760.5	$ 1,624.3	$ 1,473.6
On-site | Asia | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	580.8	523.1	1,150.5	1,052.4
On-site | Europe | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	274.6	249.2	538.6	477.5
On-site | Middle East and India | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	15.9	19.7	32.2	37.3
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	$ 1,323.0	$ 1,269.0	$ 2,674.6	$ 2,615.4
Percent sales by supply mode	42.00%	44.00%	43.00%	45.00%
Merchant | Americas | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	$ 543.5	$ 526.7	$ 1,101.3	$ 1,101.2
Merchant | Asia | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	251.8	251.0	513.6	538.8
Merchant | Europe | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	514.4	478.2	1,032.4	947.1
Merchant | Middle East and India | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	13.3	13.1	27.3	28.3
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	$ 137.1	$ 94.7	$ 254.1	$ 191.5
Percent sales by supply mode	4.00%	3.00%	4.00%	3.00%
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	$ 137.1	$ 94.7	$ 254.1	$ 191.5
Financing And Lease Arrangment | 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%