Business Segments - Schedule of Reconciliation of Operating Income to Income Before Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Segment Reporting Information
Net sales	$ 530,765	$ 543,744
Less:
Cost of sales	(412,703)	(431,700)
Amortization	(4,628)	(5,314)
Operating income	20,513	9,107
Gain on sale of former joint venture facility	3,477	0
Interest expense - net	(4,992)	(5,528)
Other expense - net	(1,076)	(2,635)
Income before income taxes	14,445	944
Rail, Technologies, and Services
Segment Reporting Information
Net sales	326,869	312,160
Infrastructure Solutions
Segment Reporting Information
Net sales	203,896	231,584
Operating Segments
Segment Reporting Information
Net sales	530,765	543,744
Less:
Cost of sales	(412,703)	(431,700)
Selling and administrative employment costs	(55,870)	(58,188)
Purchased services	(13,746)	(13,661)
General administrative costs	(12,531)	(13,953)
Amortization	(4,628)	(5,314)
Operating income	31,287	20,928
Operating Segments | Rail, Technologies, and Services
Segment Reporting Information
Net sales	326,869	312,160
Less:
Cost of sales	(254,400)	(247,126)
Selling and administrative employment costs	(32,002)	(33,181)
Purchased services	(7,410)	(7,264)
General administrative costs	(7,796)	(9,011)
Amortization	(3,349)	(3,272)
Operating income	21,912	12,306
Operating Segments | Infrastructure Solutions
Segment Reporting Information
Net sales	203,896	231,584
Less:
Cost of sales	(158,303)	(184,574)
Selling and administrative employment costs	(23,868)	(25,007)
Purchased services	(6,336)	(6,397)
General administrative costs	(4,735)	(4,942)
Amortization	(1,279)	(2,042)
Operating income	9,375	8,622
Corporate And Reconciling Items
Less:
Gain on sale of former joint venture facility	3,477
Interest expense - net	(4,992)	(5,528)
Other expense - net	(1,076)	(2,635)
Public company costs	(5,755)	(4,814)
Corporate executive management costs	(5,726)	(3,807)
Corporate management stock-based compensation	(2,065)	(2,816)
Other corporate expenses	$ (705)	$ (384)