Supplemental Information (NEOM Green Hydrogen Project) (Details) - USD ($) $ in Millions	3 Months Ended
Dec. 31, 2022	Sep. 30, 2022
Variable Interest Entity [Line Items]
Cash and cash items	$ 3,131.0	$ 2,711.0
Other receivables and current assets	542.9	515.8
Plant and equipment, net	15,039.2	14,160.5
Payables and accrued liabilities	2,552.0	2,771.6
Long-term debt – related party	658.4	652.0
Noncontrolling Interests	581.7	558.4
Variable Interest Entity, Primary Beneficiary \| NEOM Green Hydrogen Company
Variable Interest Entity [Line Items]
Cash and cash items	224.0	275.0
Other receivables and current assets	29.0	23.0
Plant and equipment, net	332.0	219.0
Payables and accrued liabilities	68.0	58.0
Long-term debt – related party	447.0	447.0
Noncontrolling Interests	$ 31.0	$ 30.0
Variable Interest Entity, Ownership interest by Air Products (percent)	33.30%

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