Revenue - Sales by Major Product Line (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Disaggregation of Revenue
Total net sales	$ 115,488	$ 98,794
Rail, Technologies, and Services
Disaggregation of Revenue
Total net sales	64,384	63,710
Precast Concrete Products
Disaggregation of Revenue
Total net sales	24,288	15,010
Steel Products and Measurement
Disaggregation of Revenue
Total net sales	26,816	20,074
Rail Products and Global Friction Management | Rail, Technologies, and Services
Disaggregation of Revenue
Total net sales	56,048	51,651
Technology Services and Solutions | Rail, Technologies, and Services
Disaggregation of Revenue
Total net sales	8,336	12,059
Precast Concrete Buildings | Precast Concrete Products
Disaggregation of Revenue
Total net sales	10,886	9,970
Other Precast Concrete Products | Precast Concrete Products
Disaggregation of Revenue
Total net sales	13,402	5,040
Fabricated Steel Products | Steel Products and Measurement
Disaggregation of Revenue
Total net sales	10,517	12,604
Coatings and Measurement | Steel Products and Measurement
Disaggregation of Revenue
Total net sales	$ 16,299	$ 7,470