Income Taxes (Tables)

12 Months Ended

Sep. 30, 2025

Income Tax Disclosure [Abstract]

Schedule of components of income tax expense (benefit)

	Year Ended September 30,
	2025		2024		2023
Current:
Federal	$	74.3	$	73.1	$	49.1
State	19.2		17.8		10.9
Foreign	(0.3)		0.7		0.9
	93.2		91.6		60.9
Deferred:
Federal	(16.7)		(7.1)		(4.9)
State	(3.7)		(1.6)		(1.1)
	(20.4)		(8.7)		(6.0)
Income tax expense	$	72.8	$	82.9	$	54.9

Schedule of effective income tax rate reconciliation

	Year Ended September 30,
	2025		2024		2023
Computed tax at federal statutory rate (21%)	$	60.7	$	69.2	$	46.3
State income taxes, net of effect on federal tax	12.6		13.5		8.4
Non-deductible compensation	5.6		3.2		1.9
Other, net (none in excess of 5% of computed tax)	(6.1)		(3.0)		(1.7)
Income tax expense	$	72.8	$	82.9	$	54.9

Schedule of deferred tax assets and liabilities

	September 30, 2025						September 30, 2024
	Assets		Liabilities		Net		Assets		Liabilities		Net
Accrued liabilities	$	26.4	$	—	$	26.4	6.7		—		6.7
Accrued vacation, incentive and severance	4.1		—		4.1		5.0		—		5.0
Capitalized research and development	8.6		—		8.6		4.7		—		4.7
Inventory	4.5		—		4.5		4.2		—		4.2
Stock-based compensation awards	2.3		—		2.3		3.0		—		3.0
Lease liabilities	6.0		—		6.0		1.0		—		1.0
Intangible assets	—		(13.1)		(13.1)		—		(10.9)		(10.9)
ROU assets	—		(6.0)		(6.0)		—		(1.0)		(1.0)
Property	—		(0.4)		(0.4)		—		(0.2)		(0.2)
Other items	—		(0.4)		(0.4)		—		—		—
Total deferred income taxes	$	51.9	$	(19.9)	$	32.0	$	24.6	$	(12.1)	$	12.5