Supplemental Information (Other Noncurrent Liabilities) (Details) - USD ($) $ in Millions	Sep. 30, 2022	Sep. 30, 2021
Disclosure Text Block Supplement [Abstract]
Operating lease liabilities	$ 592.1	$ 503.4
Asset retirement obligations	265.0	258.0
Pension benefits	190.0	255.3
Postretirement benefits	15.0	22.1
Derivative instruments	138.2	52.7
Long-term accrued income taxes related to U.S. tax reform	134.6	157.1
Contingencies related to uncertain tax positions	95.6	111.8
Contract liabilities	67.2	58.4
Environmental liabilities	61.8	68.5
Other	131.7	153.6
Other noncurrent liabilities	$ 1,691.2	$ 1,640.9