Revenue Recognition (Disaggregation of Revenue) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Disaggregation of Revenue [Line Items]
Sales	$ 2,945.1	$ 2,502.0	$ 5,939.3	$ 4,877.2
Operating Segments
Disaggregation of Revenue [Line Items]
Sales	$ 2,945.1	$ 2,502.0	$ 5,939.3	$ 4,877.2
Percent sales by supply mode	100.00%	100.00%	100.00%	100.00%
Americas | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	$ 1,186.6	$ 1,056.1	$ 2,410.7	$ 1,989.1
Asia | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	751.2	697.5	1,531.6	1,415.0
Europe | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	738.6	558.4	1,482.8	1,101.9
Middle East and India | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	28.9	26.2	52.6	45.7
Corporate and other | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	239.8	163.8	461.6	325.5
On-site | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	$ 1,486.2	$ 1,255.0	$ 3,077.3	$ 2,399.9
Percent sales by supply mode	51.00%	50.00%	52.00%	49.00%
On-site | Americas | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	$ 716.5	$ 636.7	$ 1,514.1	$ 1,178.0
On-site | Asia | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	460.4	416.0	912.0	830.9
On-site | Europe | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	292.0	182.7	617.6	359.2
On-site | Middle East and India | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	17.3	19.6	33.6	31.8
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	$ 1,219.1	$ 1,083.2	$ 2,400.4	$ 2,151.8
Percent sales by supply mode	41.00%	43.00%	40.00%	44.00%
Merchant | Americas | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	$ 470.1	$ 419.4	$ 896.6	$ 811.1
Merchant | Asia | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	290.8	281.5	619.6	584.1
Merchant | Europe | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	446.6	375.7	865.2	742.7
Merchant | Middle East and India | Operating Segments
Disaggregation of Revenue [Line Items]
Sales	11.6	6.6	19.0	13.9
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	$ 239.8	$ 163.8	$ 461.6	$ 325.5
Percent sales by supply mode	8.00%	7.00%	8.00%	7.00%
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	$ 239.8	$ 163.8	$ 461.6	$ 325.5