Property, Plant and Equipment - Schedule of Property, Plant and Equipment (Details) - USD ($) $ in Millions		Jun. 30, 2022	Sep. 30, 2021
Property, plant and equipment at cost:
Property, plant and equipment, at cost		$ 19,279.6	$ 18,719.1
Less: accumulated depreciation, depletion and amortization		(9,221.2)	(8,149.0)
Property, plant and equipment, net		10,058.4	10,570.1
Land and Buildings [Member]
Property, plant and equipment at cost:
Property, plant and equipment, at cost		2,696.4	2,626.0
Machinery and Equipment [Member]
Property, plant and equipment at cost:
Property, plant and equipment, at cost		16,359.8	15,853.1
Forestlands and Mineral Rights [Member]
Property, plant and equipment at cost:
Property, plant and equipment, at cost	[1]	98.1	120.0
Transportation Equipment [Member]
Property, plant and equipment at cost:
Property, plant and equipment, at cost		26.1	26.1
Leasehold Improvements [Member]
Property, plant and equipment at cost:
Property, plant and equipment, at cost		$ 99.2	$ 93.9

[1] In the third quarter ended June 30, 2022, we recorded a $26.0 million pre-tax non-cash impairment of certain mineral rights. With the impairment, we have no remaining mineral rights at June 30, 2022.