Restructuring and Other Charges - Restructuring and Related Costs (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Restructuring Reserve [Roll Forward]
Restructuring charges	$ 0.2	$ 10.2	$ 3.1	$ 10.2
Cost of Sales
Restructuring Reserve [Roll Forward]
Restructuring charges	0.1	3.6	4.7	3.6
Selling, General and Administrative Expenses
Restructuring Reserve [Roll Forward]
Restructuring charges	0.1	6.6	(1.6)	6.6
Access Equipment
Restructuring Reserve [Roll Forward]
Restructuring charges	0.2	7.6	3.4	7.6
Access Equipment | Cost of Sales
Restructuring Reserve [Roll Forward]
Restructuring charges	0.1	2.6	4.6	2.6
Access Equipment | Selling, General and Administrative Expenses
Restructuring Reserve [Roll Forward]
Restructuring charges	$ 0.1	5.0	(1.2)	5.0
Commercial
Restructuring Reserve [Roll Forward]
Restructuring charges		1.5	0.1	1.5
Commercial | Cost of Sales
Restructuring Reserve [Roll Forward]
Restructuring charges		0.7	0.1	0.7
Commercial | Selling, General and Administrative Expenses
Restructuring Reserve [Roll Forward]
Restructuring charges		0.8		0.8
Fire & Emergency
Restructuring Reserve [Roll Forward]
Restructuring charges		1.1		1.1
Fire & Emergency | Cost of Sales
Restructuring Reserve [Roll Forward]
Restructuring charges		0.3		0.3
Fire & Emergency | Selling, General and Administrative Expenses
Restructuring Reserve [Roll Forward]
Restructuring charges		$ 0.8		$ 0.8
Corporate
Restructuring Reserve [Roll Forward]
Restructuring charges			(0.4)
Corporate | Selling, General and Administrative Expenses
Restructuring Reserve [Roll Forward]
Restructuring charges			$ (0.4)