Revenue Recognition - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended
Dec. 31, 2021	Dec. 31, 2020
Disaggregation Of Revenue [Line Items]
Net sales	$ 1,791.7	$ 1,576.5
Intersegment Eliminations
Disaggregation Of Revenue [Line Items]
Net sales	(2.5)	(7.1)
Transferred at Point in Time
Disaggregation Of Revenue [Line Items]
Net sales	1,170.6	944.3
Transferred at Point in Time \| Intersegment Eliminations
Disaggregation Of Revenue [Line Items]
Net sales	(2.7)	(7.1)
Transferred over Time
Disaggregation Of Revenue [Line Items]
Net sales	621.1	632.2
Transferred over Time \| Intersegment Eliminations
Disaggregation Of Revenue [Line Items]
Net sales	0.2
Access Equipment
Disaggregation Of Revenue [Line Items]
Net sales	833.3	562.4
Access Equipment \| Operating Segments
Disaggregation Of Revenue [Line Items]
Net sales	833.5	563.7
Access Equipment \| Intersegment Eliminations
Disaggregation Of Revenue [Line Items]
Net sales	0.2	1.3
Access Equipment \| Transferred at Point in Time \| Operating Segments
Disaggregation Of Revenue [Line Items]
Net sales	818.8	548.1
Access Equipment \| Transferred over Time \| Operating Segments
Disaggregation Of Revenue [Line Items]
Net sales	14.7	15.6
Defense
Disaggregation Of Revenue [Line Items]
Net sales	531.1	550.0
Defense \| Operating Segments
Disaggregation Of Revenue [Line Items]
Net sales	531.5	550.3
Defense \| Intersegment Eliminations
Disaggregation Of Revenue [Line Items]
Net sales	0.4	0.3
Defense \| Transferred at Point in Time \| Operating Segments
Disaggregation Of Revenue [Line Items]
Net sales	4.0	19.6
Defense \| Transferred over Time \| Operating Segments
Disaggregation Of Revenue [Line Items]
Net sales	527.5	530.7
Fire & Emergency
Disaggregation Of Revenue [Line Items]
Net sales	217.0	269.8
Fire & Emergency \| Operating Segments
Disaggregation Of Revenue [Line Items]
Net sales	218.6	273.9
Fire & Emergency \| Intersegment Eliminations
Disaggregation Of Revenue [Line Items]
Net sales	1.6	4.1
Fire & Emergency \| Transferred at Point in Time \| Operating Segments
Disaggregation Of Revenue [Line Items]
Net sales	214.7	268.9
Fire & Emergency \| Transferred over Time \| Operating Segments
Disaggregation Of Revenue [Line Items]
Net sales	3.9	5.0
Commercial
Disaggregation Of Revenue [Line Items]
Net sales	210.2	194.2
Commercial \| Operating Segments
Disaggregation Of Revenue [Line Items]
Net sales	210.6	195.7
Commercial \| Intersegment Eliminations
Disaggregation Of Revenue [Line Items]
Net sales	0.4	1.5
Commercial \| Transferred at Point in Time \| Operating Segments
Disaggregation Of Revenue [Line Items]
Net sales	135.8	114.8
Commercial \| Transferred over Time \| Operating Segments
Disaggregation Of Revenue [Line Items]
Net sales	$ 74.8	$ 80.9