Business Segments - Schedule of Reconciliation of Operating Income to Income Before Taxes (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Segment Reporting Information
Net sales	$ 97,792	$ 124,320
Less:
Cost of sales	(77,641)	(98,144)
Amortization expense	(1,122)	(1,217)
Operating (loss) income	(1,923)	5,566
Gain on sale of former joint venture facility	0	3,477
Interest expense - net	(1,143)	(1,125)
Other income - net	318	253
(Loss) income before income taxes	(2,748)	4,694
Rail, Technologies, and Services
Segment Reporting Information
Net sales	54,015	82,623
Infrastructure Solutions
Segment Reporting Information
Net sales	43,777	41,697
Operating Segments
Segment Reporting Information
Net sales	97,792	124,320
Less:
Cost of sales	(77,641)	(98,144)
Selling and administrative employment costs	(12,963)	(13,300)
Purchased services	(3,031)	(3,517)
General administrative costs	(3,335)	(2,752)
Amortization expense	(1,122)	(1,217)
Operating (loss) income	(300)	5,390
Operating Segments | Rail, Technologies, and Services
Segment Reporting Information
Net sales	54,015	82,623
Less:
Cost of sales	(41,986)	(64,052)
Selling and administrative employment costs	(7,399)	(7,482)
Purchased services	(1,673)	(1,939)
General administrative costs	(1,993)	(1,501)
Amortization expense	(820)	(871)
Operating (loss) income	144	6,778
Operating Segments | Infrastructure Solutions
Segment Reporting Information
Net sales	43,777	41,697
Less:
Cost of sales	(35,655)	(34,092)
Selling and administrative employment costs	(5,564)	(5,818)
Purchased services	(1,358)	(1,578)
General administrative costs	(1,342)	(1,251)
Amortization expense	(302)	(346)
Operating (loss) income	(444)	(1,388)
Corporate And Reconciling Items
Less:
Gain on sale of former joint venture facility		3,477
Interest expense - net	(1,143)	(1,125)
Other income - net	318	253
Public company costs	(1,154)	(1,219)
Corporate executive management costs	(220)	(1,407)
Corporate management stock-based compensation	(278)	(599)
Other corporate expenses - net	$ 29	$ (76)