Retirement Benefit Plans - Net Plan Assets Recognized in the Consolidated Balance Sheets (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Sep. 30, 2021
Reconciliation of funded status:
Plan assets less than projected benefit obligations	$ (4,858)	$ (6,119)
Amounts recognized in accumulated other comprehensive loss:
Net loss	6,271	7,482
Net amount recognized in the consolidated balance sheets	1,413	1,363
Amounts recognized in the consolidated balance sheets are:
Accumulated other comprehensive loss – pretax	6,271	7,482
Accrued liabilities
Amounts recognized in the consolidated balance sheets are:
Liabilities	(46)	(46)
Pension liability
Amounts recognized in the consolidated balance sheets are:
Liabilities	$ (4,812)	$ (6,073)