Revenue Recognition - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2023	Dec. 31, 2022	Sep. 30, 2021
Disaggregation Of Revenue [Line Items]
Net sales	$ 1,791.7	$ 9,657.9	$ 8,282.0	$ 7,737.3
Operating Segments
Disaggregation Of Revenue [Line Items]
Net sales	1,791.7	9,657.9	8,282.0	7,737.3
Intersegment Eliminations
Disaggregation Of Revenue [Line Items]
Net sales	(2.5)	(8.4)	(7.1)	(24.6)
Transferred at Point in Time
Disaggregation Of Revenue [Line Items]
Net sales	1,170.6	6,941.6	5,686.5	4,764.0
Transferred at Point in Time | Intersegment Eliminations
Disaggregation Of Revenue [Line Items]
Net sales	(2.7)	(8.4)	(7.1)	(25.1)
Transferred over Time
Disaggregation Of Revenue [Line Items]
Net sales	621.1	2,716.3	2,595.5	2,973.3
Transferred over Time | Intersegment Eliminations
Disaggregation Of Revenue [Line Items]
Net sales	0.2			0.5
Access Equipment | Operating Segments
Disaggregation Of Revenue [Line Items]
Net sales	833.5	4,990.0	3,972.1	3,072.1
Access Equipment | Transferred at Point in Time | Operating Segments
Disaggregation Of Revenue [Line Items]
Net sales	818.8	4,936.5	3,923.4	3,006.9
Access Equipment | Transferred over Time | Operating Segments
Disaggregation Of Revenue [Line Items]
Net sales	14.7	53.5	48.7	65.2
Defense
Disaggregation Of Revenue [Line Items]
Net sales	531.1	2,092.0	2,139.9	2,524.1
Defense | Operating Segments
Disaggregation Of Revenue [Line Items]
Net sales	531.5	2,098.2	2,141.3	2,525.6
Defense | Intersegment Eliminations
Disaggregation Of Revenue [Line Items]
Net sales	0.4	6.2	1.4	1.5
Defense | Transferred at Point in Time | Operating Segments
Disaggregation Of Revenue [Line Items]
Net sales	4.0	12.1	13.0	43.5
Defense | Transferred over Time | Operating Segments
Disaggregation Of Revenue [Line Items]
Net sales	527.5	2,086.1	2,128.3	2,482.1
Vocational
Disaggregation Of Revenue [Line Items]
Net sales	427.2	2,575.9	2,170.0	2,145.2
Vocational | Operating Segments
Disaggregation Of Revenue [Line Items]
Net sales	429.2	2,578.1	2,175.7	2,164.2
Vocational | Intersegment Eliminations
Disaggregation Of Revenue [Line Items]
Net sales	2.0	2.2	5.7	19.0
Vocational | Transferred at Point in Time | Operating Segments
Disaggregation Of Revenue [Line Items]
Net sales	350.5	2,001.4	1,757.2	1,738.7
Vocational | Transferred over Time | Operating Segments
Disaggregation Of Revenue [Line Items]
Net sales	$ 78.7	$ 576.7	$ 418.5	$ 425.5