Retirement Benefit Plans - Components of Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Retirement Benefits [Abstract]
Service cost	$ 45	$ 6	$ 135	$ 18
Interest cost	271	274	813	824
Expected return on plan assets	(261)	(277)	(782)	(831)
Amortization of net loss	44	77	130	230
Settlement cost	60	78	60	78
Net periodic pension cost	$ 159	$ 158	$ 356	$ 319