Business Segment Information - Schedule of Income (Loss) from Continuing operations by Product Lines and Reportable Segments (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020
Operating income (loss):
Operating income (loss)		$ 140.8	$ 133.6	$ 236.7	$ 242.7
Interest expense, net of interest income		(11.2)	(20.7)	(22.6)	(32.5)
Miscellaneous other expense		3.1	(5.8)	1.6	(6.2)
Income before income taxes and earnings (losses) of unconsolidated affiliates		132.7	107.1	215.7	204.0
Operating Segments | Access Equipment
Operating income (loss):
Operating income (loss)	[1]	80.5	70.8	105.4	139.8
Operating Segments | Defense
Operating income (loss):
Operating income (loss)	[2]	35.5	59.7	88.3	90.7
Operating Segments | Fire & Emergency
Operating income (loss):
Operating income (loss)	[2]	47.4	19.0	82.5	49.9
Operating Segments | Commercial
Operating income (loss):
Operating income (loss)		18.8	8.1	30.7	25.9
Corporate, Non-segment
Operating income (loss):
Operating income (loss)		$ (41.4)	$ (24.0)	$ (70.2)	$ (63.6)

[1] Results for the three and six months ended March 31, 2021 include a $1.6 million benefit and a $3.2 million charge for restructuring, respectively. The Company incurred additional charges of $3.8 million and $7.0 million of other costs related to restructuring plans in the three and six months ended March 31, 2021, respectively.

[2] Results have been reclassified to reflect the move of the airport snow removal vehicle business from the Fire & Emergency segment to the Defense segment.