Business Segments - Reconciliation of Revenue from Segments to Consolidated (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Segment Reporting Information
Net Sales	$ 145,345	$ 130,015	$ 408,867	$ 360,324
Segment Operating Profit (Loss)	2,685	(1,120)	9,537	(927)
Operating Segments
Segment Reporting Information
Net Sales	145,345	130,015	408,867	360,324
Segment Operating Profit (Loss)	5,733	2,087	17,144	4,822
Rail, Technologies, and Services
Segment Reporting Information
Net Sales	86,866	77,350	242,866	222,857
Rail, Technologies, and Services | Operating Segments
Segment Reporting Information
Net Sales	86,866	77,350	242,866	222,857
Segment Operating Profit (Loss)	3,865	539	12,880	5,576
Precast Concrete Products
Segment Reporting Information
Net Sales	38,642	28,856	96,795	67,477
Precast Concrete Products | Operating Segments
Segment Reporting Information
Net Sales	38,642	28,856	96,795	67,477
Segment Operating Profit (Loss)	3,389	1,245	4,337	329
Steel Products and Measurement
Segment Reporting Information
Net Sales	19,837	23,809	69,206	69,990
Steel Products and Measurement | Operating Segments
Segment Reporting Information
Net Sales	19,837	23,809	69,206	69,990
Segment Operating Profit (Loss)	$ (1,521)	$ 303	$ (73)	$ (1,083)