Goodwill and Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Goodwill and Intangible Assets
Goodwill Carrying Amount	$ 46,008	$ 61,293
Goodwill	76,593	76,593
Accumulated Impairment charges	(30,585)	(15,300)
Professional Services reporting unit [Member]
Goodwill and Intangible Assets
Goodwill Carrying Amount	46,008	60,210
Goodwill	75,510	75,510
Accumulated Impairment charges	(29,502)	(15,300)
Industrial Services reporting unit [Member]
Goodwill and Intangible Assets
Goodwill Carrying Amount	0	1,083
Goodwill	1,083	1,083
Accumulated Impairment charges	$ (1,083)	$ 0