Revenue - Timing of Transfer (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
Point in time
Disaggregation of Revenue
Total net sales	99,115	83,477	263,019	281,533
Over time
Disaggregation of Revenue
Total net sales	30,900	46,576	97,305	119,122
Rail, Technologies, and Services
Disaggregation of Revenue
Total net sales	77,350	73,942	222,857	228,956
Rail, Technologies, and Services | Point in time
Disaggregation of Revenue
Total net sales	64,913	54,470	179,951	178,225
Rail, Technologies, and Services | Over time
Disaggregation of Revenue
Total net sales	12,437	19,472	42,906	50,731
Precast Concrete Products
Disaggregation of Revenue
Total net sales	28,856	17,972	67,477	50,723
Precast Concrete Products | Point in time
Disaggregation of Revenue
Total net sales	13,331	4,088	26,171	10,209
Precast Concrete Products | Over time
Disaggregation of Revenue
Total net sales	15,525	13,884	41,306	40,514
Steel Products and Measurement
Disaggregation of Revenue
Total net sales	23,809	38,139	69,990	120,976
Steel Products and Measurement | Point in time
Disaggregation of Revenue
Total net sales	20,871	24,919	56,897	93,099
Steel Products and Measurement | Over time
Disaggregation of Revenue
Total net sales	$ 2,938	$ 13,220	$ 13,093	$ 27,877