Leases - Summary of Supplemental Balance Sheet Information Related to Leases (Details) - USD ($) $ in Millions	Dec. 31, 2023	Sep. 30, 2023
Supplementary Information Balance Sheets [Abstract]
Operating lease right-of-use asset	$ 622.2	$ 648.5
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	Other noncurrent assets	Other noncurrent assets
Current operating lease liabilities	$ 195.5	$ 202.4
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Other current liabilities	Other current liabilities
Noncurrent operating lease liabilities	$ 477.4	$ 499.7
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Other noncurrent liabilities	Other noncurrent liabilities
Total operating lease liabilities	$ 672.9	$ 702.1
Property, plant and equipment	453.5	400.6
Accumulated depreciation	(65.7)	(105.3)
Property, plant and equipment, net	387.8	295.3
Current finance lease liabilities	$ 25.9	$ 62.9
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]	Current portion of debt	Current portion of debt
Noncurrent finance lease liabilities	$ 495.3	$ 409.7
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Long-term debt due after one year	Long-term debt due after one year
Total finance lease liabilities	$ 521.2	$ 472.6