Revenue - Timing of Transfer (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Disaggregation of Revenue
Total net sales	$ 145,345	$ 130,015	$ 408,867	$ 360,324
Bridge Grid Deck Product | Discontinued Operations
Disaggregation of Revenue
Total net sales	283	2,967	3,749	12,975
Disposal Group, Including Discontinued Operation, Revenue	1,977
Point in time
Disaggregation of Revenue
Total net sales	110,780	99,115	304,612	263,019
Over time
Disaggregation of Revenue
Total net sales	34,565	30,900	104,255	97,305
Rail, Technologies, and Services
Disaggregation of Revenue
Total net sales	86,866	77,350	242,866	222,857
Rail, Technologies, and Services | Point in time
Disaggregation of Revenue
Total net sales	72,246	64,913	202,003	179,951
Rail, Technologies, and Services | Over time
Disaggregation of Revenue
Total net sales	14,620	12,437	40,863	42,906
Precast Concrete Products
Disaggregation of Revenue
Total net sales	38,642	28,856	96,795	67,477
Precast Concrete Products | Point in time
Disaggregation of Revenue
Total net sales	18,516	13,331	46,458	26,171
Precast Concrete Products | Over time
Disaggregation of Revenue
Total net sales	20,126	15,525	50,337	41,306
Steel Products and Measurement
Disaggregation of Revenue
Total net sales	19,837	23,809	69,206	69,990
Steel Products and Measurement | Point in time
Disaggregation of Revenue
Total net sales	20,018	20,871	56,151	56,897
Steel Products and Measurement | Over time
Disaggregation of Revenue
Total net sales	$ (181)	$ 2,938	$ 13,055	$ 13,093