Contingencies, Significant Estimates and Concentrations - Schedule of Significant Portion of Revenues from the Department of Defense (Details) - USD ($) $ in Millions	3 Months Ended																12 Months Ended
	Dec. 31, 2022	[1]	Sep. 30, 2022	[2]	Jun. 30, 2022	Mar. 31, 2022	[3]	Dec. 31, 2021	Sep. 30, 2021	[4]	Jun. 30, 2021	[5]	Mar. 31, 2021	[6]	Dec. 31, 2020	[7]	Dec. 31, 2022	Sep. 30, 2021	Sep. 30, 2020
Disaggregation Of Revenue [Line Items]
Net sales	$ 2,203.6		$ 2,066.7		$ 2,066.0	$ 1,945.7		$ 1,791.7	$ 2,063.0		$ 2,208.8		$ 1,889.0		$ 1,576.5		$ 8,282.0	$ 7,737.3	$ 6,856.8
DoD
Disaggregation Of Revenue [Line Items]
Net sales								521.2									1,995.8	2,395.1	2,300.4
Foreign Military
Disaggregation Of Revenue [Line Items]
Net sales								0.5									76.2	139.2	71.2
Total DoD Sales
Disaggregation Of Revenue [Line Items]
Net sales								$ 521.7									$ 2,072.0	$ 2,534.3	$ 2,371.6

[1] The fourth quarter of fiscal 2022 was impacted by a $5.6 million ($4.3 million after-tax) intangible asset impairment charge in the Defense segment and a $33.6 million ($25.7 million after-tax) pension settlement charge.

[2] The third quarter of fiscal 2022 was impacted by expense of $4.6 million to eliminate cumulative translation adjustments upon liquidation of foreign entities in the Access Equipment segment and a $2.1 million intangible asset impairment charge in the Commercial segment.

[3] The first quarter of fiscal 2022 was impacted by tax expense of $18.1 million for anti-hybrid tax on prior period income.

[4] The fourth quarter of the year ended September 30, 2021 was impacted by a tax benefit of $11.7 million for the revaluation of deferred tax liabilities and a tax benefit of $5.4 million for net operating loss carrybacks.

[5] The third quarter of the year ended September 30, 2021 was impacted a tax benefit of $69.9 million for net operating loss carrybacks and $1.3 million ($1.4 million after-tax) of restructuring-related costs in the Access Equipment segment.

[6] The second quarter of the year ended September 30, 2021 was impacted by $2.2 million ($2.5 million after-tax) of restructuring-related costs in the Access Equipment segment.

[7] The first quarter of the year ended September 30, 2021 was impacted by $8.0 million ($7.8 million after-tax) of restructuring-related costs in the Access Equipment segment.