Reportable Segments - Schedule of Reportable Segment Information (Details) - USD ($) $ in Thousands		3 Months Ended
		Dec. 31, 2023	Dec. 31, 2022	Sep. 30, 2023
Segment Reporting Information [Line Items]
Net Revenues		$ 24,920	$ 21,558
Operating income (loss)		(8,934)	(2,680)
Identifiable Assets		125,042		$ 137,021
Operating Segments | Semiconductor
Segment Reporting Information [Line Items]
Net Revenues		17,527	16,887
Operating income (loss)		1,081	869
Identifiable Assets		67,187		72,466
Operating Segments | Material and Substrate
Segment Reporting Information [Line Items]
Net Revenues		7,393	4,671
Operating income (loss)		(7,844)	633
Identifiable Assets		51,287		61,576
Non-Segment Related
Segment Reporting Information [Line Items]
Operating income (loss)		(2,171)	$ (4,182)
Identifiable Assets	[1]	$ 6,568		$ 2,979

[1] * Non-segment related assets include cash, property, and other assets.