Business Segments - Narrative (Details) $ in Thousands				3 Months Ended		6 Months Ended		9 Months Ended	10 Months Ended
	Jun. 28, 2024 USD ($)	Nov. 17, 2023 USD ($)	Jun. 30, 2023 USD ($)	Jun. 30, 2024 USD ($)	Jun. 30, 2023 USD ($)	Jun. 30, 2024 USD ($) segment	Jun. 30, 2023 USD ($)	Sep. 30, 2023 segment	Jun. 30, 2024 USD ($)
Segment Reporting Information
Number of reportable segments | segment						2		3
Proceeds from business dispositions						$ 0	$ 7,706
Gain (loss) on asset divestiture						0	(3,074)
(Gain) on sale of former joint venture facility				$ 0	$ 0	(3,477)	0
Total net sales				140,796	148,034	265,116	263,522
Exit costs incurred				(84)	1,084	(337)	2,933
Cougar purchase accounting adjustment
Segment Reporting Information
Consideration transferred to acquire operating assets		$ 1,644
Disposal Group, Not Discontinued Operations | Bridge Grid Deck Product
Segment Reporting Information
Proceeds from business dispositions	$ 1,300
Gain (loss) on asset divestiture	$ 815
Total net sales				1,157	1,975	1,967	3,466
Exit costs incurred				$ 0		0			$ 1,476
Personnel expenses									740
Inventory write-down									474
Other exit costs									$ 262
Coatings and Measurement
Segment Reporting Information
Proceeds from business dispositions						5,344
Rail Products
Segment Reporting Information
Proceeds from business dispositions			$ 2,362
Gain (loss) on asset divestiture					$ (1,009)	$ (2,065)	$ (1,009)