Summary of Significant Accounting Policies - Goodwill and Other Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Intangible Assets
Useful life	15 years
Goodwill impairment charges	$ 0	$ 0	$ 0
Change to goodwill	0	0	0
Amortization of customer relationships, patents, non-competes and other intangibles	579	780	$ 467
Total intangible assets, Gross Amount	6,980	7,000
Finite-lived intangible assets, Accumulated Amortization	(1,325)	(2,091)
Carrying Amount	5,655	4,909
Customer relationships
Intangible Assets
Finite-lived intangible assets Gross Amount	2,100	2,100
Finite-lived intangible assets, Accumulated Amortization	(1,257)	(1,128)
Finite-lived intangible assets, Carrying Amount	843	972
Other Intangible Assets
Intangible Assets
Finite-lived intangible assets Gross Amount	1,080	1,100
Finite-lived intangible assets, Accumulated Amortization	(68)	(963)
Finite-lived intangible assets, Carrying Amount	1,012	137
Trademarks
Intangible Assets
Indefinite-lived intangible assets	$ 3,800	3,800
Finite-lived intangible assets, Carrying Amount		$ 3,800