Business Segments - Schedule of Reconciliation of Operating Income to Income Before Taxes (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Segment Reporting Information
Net sales	$ 121,144	$ 97,792
Less:
Cost of sales	(95,448)	(77,641)
Amortization expense	(618)	(1,122)
Operating income (loss)	2,045	(1,923)
Interest expense - net	(851)	(1,143)
Other income - net	217	318
Income (loss) before income taxes	1,411	(2,748)
Rail, Technologies, and Services
Segment Reporting Information
Net sales	74,776	54,015
Infrastructure Solutions
Segment Reporting Information
Net sales	46,368	43,777
Operating Segments
Segment Reporting Information
Net sales	121,144	97,792
Less:
Cost of sales	(95,448)	(77,641)
Selling and administrative employment costs	(13,410)	(12,963)
Purchased services	(3,319)	(3,031)
General administrative costs	(3,000)	(3,335)
Amortization expense	(618)	(1,122)
Operating income (loss)	5,349	(300)
Operating Segments | Rail, Technologies, and Services
Segment Reporting Information
Net sales	74,776	54,015
Less:
Cost of sales	(58,634)	(41,986)
Selling and administrative employment costs	(7,567)	(7,399)
Purchased services	(1,773)	(1,673)
General administrative costs	(1,645)	(1,993)
Amortization expense	(337)	(820)
Operating income (loss)	4,820	144
Operating Segments | Infrastructure Solutions
Segment Reporting Information
Net sales	46,368	43,777
Less:
Cost of sales	(36,814)	(35,655)
Selling and administrative employment costs	(5,843)	(5,564)
Purchased services	(1,546)	(1,358)
General administrative costs	(1,355)	(1,342)
Amortization expense	(281)	(302)
Operating income (loss)	529	(444)
Corporate And Reconciling Items
Less:
Interest expense - net	(851)	(1,143)
Other income - net	217	318
Public company costs	(1,105)	(1,125)
Corporate executive management costs	(790)	(220)
Corporate management stock-based compensation	$ (1,409)	$ (278)