Retirement Benefit Plans - Components of Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Retirement Benefits [Abstract]
Service cost	$ 6	$ 11
Interest cost	274	178
Expected return on plan assets	(277)	(340)
Amortization of net loss	78	119
Net periodic pension cost (benefit)	$ 81	$ (32)