Business Segments - Reconciliation of Revenue from Segments to Consolidated (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Segment Reporting Information
Net Sales	$ 148,034	$ 131,515	$ 263,522	$ 230,309
Segment Operating Profit	6,349	2,480	6,852	193
Operating Segments
Segment Reporting Information
Net Sales	148,034	131,515	263,522	230,309
Segment Operating Profit	9,379	4,635	11,411	2,735
Rail, Technologies, and Services
Segment Reporting Information
Net Sales	91,616	81,797	156,000	145,507
Rail, Technologies, and Services | Operating Segments
Segment Reporting Information
Net Sales	91,616	81,797	156,000	145,507
Segment Operating Profit	6,627	3,998	9,015	5,037
Precast Concrete Products
Segment Reporting Information
Net Sales	33,865	23,611	58,153	38,621
Precast Concrete Products | Operating Segments
Segment Reporting Information
Net Sales	33,865	23,611	58,153	38,621
Segment Operating Profit	1,296	(125)	948	(916)
Steel Products and Measurement
Segment Reporting Information
Net Sales	22,553	26,107	49,369	46,181
Steel Products and Measurement | Operating Segments
Segment Reporting Information
Net Sales	22,553	26,107	49,369	46,181
Segment Operating Profit	$ 1,456	$ 762	$ 1,448	$ (1,386)