Revenue - Disaggregation of Revenues (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Disaggregation of Revenue
Total net sales	$ 130,015	$ 130,053	$ 360,324	$ 400,655
Rail, Technologies, and Services
Disaggregation of Revenue
Total net sales	77,350	73,942	222,857	228,956
Precast Concrete Products
Disaggregation of Revenue
Total net sales	28,856	17,972	67,477	50,723
Steel Products and Measurement
Disaggregation of Revenue
Total net sales	23,809	38,139	69,990	120,976
Rail Products and Global Friction Management | Rail, Technologies, and Services
Disaggregation of Revenue
Total net sales	69,161	60,593	191,228	192,661
Technology Services and Solutions | Rail, Technologies, and Services
Disaggregation of Revenue
Total net sales	8,189	13,349	31,629	36,295
Precast Concrete Buildings | Precast Concrete Products
Disaggregation of Revenue
Total net sales	15,525	13,884	41,306	40,516
Other Precast Concrete Products | Precast Concrete Products
Disaggregation of Revenue
Total net sales	13,331	4,088	26,171	10,207
Fabricated Steel Products | Steel Products and Measurement
Disaggregation of Revenue
Total net sales	15,250	30,512	45,821	100,233
Coatings and Measurement | Steel Products and Measurement
Disaggregation of Revenue
Total net sales	$ 8,559	$ 7,627	$ 24,169	$ 20,743