The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

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Intangible Assets (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
Intangible Assets (Details) - USD ($) $ in Millions	Mar. 31, 2024	Sep. 30, 2023	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2022
Intangible Assets [Abstract]
Gross carrying value	$ 245.8		$ 245.8	$ 133.0
Accumulated amortization	(57.5)		(57.5)	(51.9)
Net intangible assets	188.3		188.3	81.1
Amortization expense			9.2	8.0	$ 8.4
Estimated Future Amortization Expense [Abstract]
Fiscal 2025	29.0		29.0
Fiscal 2026	18.0		18.0
Fiscal 2027	17.0		17.0
Fiscal 2028	17.0		17.0
Fiscal 2029	16.0		16.0
Customer Relationships [Member]
Intangible Assets [Abstract]
Gross carrying value	150.5		150.5	60.3
Accumulated amortization	(26.3)		(26.3)	(23.4)
Net intangible assets	124.2		124.2	36.9
Trade Names [Member]
Intangible Assets [Abstract]
Gross carrying value	62.8		62.8	50.1
Accumulated amortization	(18.5)		(18.5)	(15.9)
Net intangible assets	44.3		44.3	34.2
Acquired Technology [Member]
Intangible Assets [Abstract]
Gross carrying value	32.5		32.5	22.6
Accumulated amortization	(12.7)		(12.7)	(12.6)
Net intangible assets	19.8		$ 19.8	$ 10.0
Acquired Technology [Member] \| TMGcore, Inc. [Member]
Intangible Assets [Abstract]
Intangible assets acquired	11.4
Customer Relationships and Acquired Technology [Member] \| Napps [Member]
Intangible Assets [Abstract]
Intangible assets acquired		$ 2.9
Customer Relationships, Order Backlog and Trade Names [Member] \| Scott Springfield Manufacturing [Member]
Intangible Assets [Abstract]
Intangible assets acquired	$ 102.3