Acquisitions - Summary of Preliminary Fair Value of Assets and Liabilities Assumed in Acquisition (Details) - USD ($) $ in Millions		Dec. 31, 2023	Sep. 30, 2023	Dec. 01, 2022
Business Acquisition [Line Items]
Goodwill		$ 4,270.2	$ 4,248.7
Mexico Acquisition [Member]
Business Acquisition [Line Items]
Cash and cash equivalents				$ 116.3
Current assets, excluding cash and cash equivalents				697.0
Property, plant and equipment				1,380.3
Goodwill				231.2
Other noncurrent assets				101.4
Total assets acquired				2,526.2
Current portion of debt	[1]			13.2
Current liabilities, excluding debt				384.8
Long-term debt due after one year	[1]			591.4
Pension liabilities, net of current portion				35.2
Deferred income taxes				69.8
Other noncurrent liabilities				18.1
Total liabilities assumed				1,112.5
Net assets acquired				1,413.7
Measurement Period Adjustments [Member] | Mexico Acquisition [Member]
Business Acquisition [Line Items]
Current assets, excluding cash and cash equivalents	[2],[3]			(71.2)
Property, plant and equipment	[2],[3]			43.0
Goodwill	[2],[3]			6.2
Other noncurrent assets	[2],[3]			0.6
Total assets acquired	[2],[3]			(21.4)
Current liabilities, excluding debt	[2],[3]			(50.4)
Long-term debt due after one year	[1],[2],[3]			36.2
Pension liabilities, net of current portion	[2],[3]			(3.1)
Deferred income taxes	[2],[3]			(4.1)
Total liabilities assumed	[2],[3]			(21.4)
As Adjusted [Member] | Mexico Acquisition [Member]
Business Acquisition [Line Items]
Cash and cash equivalents				116.3
Current assets, excluding cash and cash equivalents				625.8
Property, plant and equipment				1,423.3
Goodwill				237.4
Other noncurrent assets				102.0
Total assets acquired				2,504.8
Current portion of debt	[1]			13.2
Current liabilities, excluding debt				334.4
Long-term debt due after one year	[1]			627.6
Pension liabilities, net of current portion				32.1
Deferred income taxes				65.7
Other noncurrent liabilities				18.1
Total liabilities assumed				1,091.1
Net assets acquired				$ 1,413.7

[1] Includes $494.8 million of debt that we assumed and repaid in connection with the closing of the Mexico Acquisition. The remaining balance relates to current and long-term portions of finance leases.

[2] The measurement period adjustments did not have a significant impact on our consolidated statements of operations in any period.

[3] The measurement period adjustments were primarily due to refinements to the carrying amounts of certain assets and liabilities. The net impact of the measurement period adjustments resulted in a net increase in goodwill.