Pension Plans - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Defined Benefit Plan Disclosure [Line Items]
Weighted average interest credit rate used in only cash balance pension plans		4.70%
Defined benefit plan, plan assets, increase (decrease) for actual return (loss)		$ 2,600	$ 5,100	$ (1,900)
Defined benefit plan, plan assets, contributions by employer		$ 3,200	$ 3,700	$ 1,300
Forecast
Defined Benefit Plan Disclosure [Line Items]
Net periodic pension income	$ 700
Defined benefit plan, plan assets, contributions by employer	600
Defined benefit plan, plan assets, contributions by employer, directly to plans	$ 3,600
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Weighted average assumptions used to determine net periodic pension cost for fiscal years ended September 30, Rate of return on plan assets		4.80%	4.80%	4.80%
Net periodic pension income		$ (369)	$ 60	$ (484)
Defined benefit plan, plan assets, increase (decrease) for actual return (loss)		2,563	5,120
Defined benefit plan, plan assets, contributions by employer		$ 3,238	$ 3,697
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate		3.80%	3.30%	4.20%
Defined Benefit Plan Assumptions Used Calculating Benefit Obligation DiscountRate Decrease			3.30%	4.20%
Pension Plan | Foreign Plan
Defined Benefit Plan Disclosure [Line Items]
Current asset allocation target for fixed income securities		100.00%