Business Segment Information - Schedule of Depreciation, Amortization and Capital Expenditure by Segment (Details) - USD ($) $ in Millions		12 Months Ended
		Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting Information [Line Items]
Depreciation and amortization		$ 104.2	$ 115.2	$ 120.5
Capital expenditures		130.2	174.2	100.1
Operating Segments | Access Equipment
Segment Reporting Information [Line Items]
Depreciation and amortization	[1]	42.1	58.2	61.1
Capital expenditures	[2]	56.5	61.4	34.2
Operating Segments | Defense
Segment Reporting Information [Line Items]
Depreciation and amortization		20.1	17.3	15.2
Capital expenditures		32.3	31.4	29.1
Operating Segments | Fire & Emergency
Segment Reporting Information [Line Items]
Depreciation and amortization		10.0	9.5	9.5
Capital expenditures		6.8	12.8	12.8
Operating Segments | Commercial
Segment Reporting Information [Line Items]
Depreciation and amortization	[3]	17.1	12.4	12.9
Capital expenditures	[2]	18.9	18.1	12.0
Corporate, Non-segment
Segment Reporting Information [Line Items]
Depreciation and amortization		14.9	17.8	21.8
Capital expenditures	[4]	$ 15.7	$ 50.5	$ 12.0

[1] Includes $2.8 million of accelerated deprecation associated with restructuring actions in fiscal 2020.

[2] Capital expenditures include both the purchase of property, plant and equipment and equipment held for rental.

[3] Includes $4.1 million of accelerated deprecation associated with restructuring actions in fiscal 2020.

[4] Capital expenditures include capital spending for the construction of the Company’s new global headquarters.