Income Taxes - Deferreds (Details) - Noncurrent - USD ($) $ in Millions	Sep. 30, 2024	Sep. 30, 2023
Deferred tax assets
Income Tax Disclosure
Deferred tax assets, accrued liabilities	$ 6.7	$ 6.0
Deferred tax assets, employee compensation	5.0	3.1
Deferred Tax Assets, Capitalized research and development	4.7	2.3
Deferred tax assets, inventory	4.2	4.4
Deferred tax assets, share-based compensation cost	3.0	2.2
Deferred Tax Liabilities, Leasing Arrangements	1.0	1.4
Deferred tax assets (liabilities), intangible assets	0.0	0.0
Deferred Tax Assets, Leasing Arrangements	0.0	0.0
Deferred tax liabilities, property, plant and equipment	0.0	0.0
Deferred tax assets, net	24.6	19.4
Deferred tax liability
Income Tax Disclosure
Deferred tax assets, accrued liabilities	0.0	0.0
Deferred tax assets, employee compensation	0.0	0.0
Deferred Tax Assets, Capitalized research and development	0.0	0.0
Deferred tax assets, inventory	0.0	0.0
Deferred tax assets, share-based compensation cost	0.0	0.0
Deferred Tax Liabilities, Leasing Arrangements	0.0	0.0
Deferred tax assets (liabilities), intangible assets	(10.9)	(13.9)
Deferred Tax Assets, Leasing Arrangements	(1.0)	(1.4)
Deferred tax liabilities, property, plant and equipment	(0.2)	(0.3)
Deferred tax liabilities, net	(12.1)	(15.6)
Total deferred income taxes
Income Tax Disclosure
Deferred tax assets, accrued liabilities	6.7	6.0
Deferred tax assets, employee compensation	5.0	3.1
Deferred Tax Assets, Capitalized research and development	4.7	2.3
Deferred tax assets, inventory	4.2	4.4
Deferred tax assets, share-based compensation cost	3.0	2.2
Deferred Tax Liabilities, Leasing Arrangements	1.0	1.4
Deferred tax assets (liabilities), intangible assets	(10.9)	(13.9)
Deferred Tax Assets, Leasing Arrangements	(1.0)	(1.4)
Deferred tax liabilities, property, plant and equipment	(0.2)	(0.3)
Deferred tax assets, net	$ 12.5	$ 3.8