Identifiable intangible assets (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Sep. 30, 2022
Finite-Lived Intangible Assets [Line Items]
Intangible assets gross	$ 4,586	$ 4,586
Accumulated amortization	4,227	4,030
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets gross	4,440	4,440
Accumulated amortization	4,081	3,885
Trademarks and Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets gross	72	72
Accumulated amortization	72	72
Noncompete Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets gross	74	74
Accumulated amortization	$ 74	$ 73