Business Segments - Reconciliation of Revenue from Segments to Consolidated (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Segment Reporting Information
Net Sales	$ 497,497	$ 513,620
Segment Operating Profit (Loss)	(7,206)	4,471
Segment Assets	365,310	342,595
Depreciation/Amortization	14,779	13,887
Expenditures for Long-Lived Assets	7,633	4,620
Rail, Technologies, and Services
Segment Reporting Information
Net Sales	300,592	299,749
Precast Concrete Products
Segment Reporting Information
Net Sales	104,212	70,990
Steel Products and Measurement
Segment Reporting Information
Net Sales	92,693	142,881
Operating Segments
Segment Reporting Information
Net Sales	497,497	513,620
Segment Operating Profit (Loss)	2,322	13,308
Segment Assets	335,225	278,725
Depreciation/Amortization	13,284	12,543
Expenditures for Long-Lived Assets	4,318	3,600
Operating Segments | Rail, Technologies, and Services
Segment Reporting Information
Net Sales	300,592	299,749
Segment Operating Profit (Loss)	11,454	14,165
Segment Assets	172,111	171,608
Depreciation/Amortization	5,620	6,089
Expenditures for Long-Lived Assets	1,218	1,081
Operating Segments | Precast Concrete Products
Segment Reporting Information
Net Sales	104,212	70,990
Segment Operating Profit (Loss)	1,692	1,545
Segment Assets	108,598	48,740
Depreciation/Amortization	3,162	1,716
Expenditures for Long-Lived Assets	2,833	2,441
Operating Segments | Steel Products and Measurement
Segment Reporting Information
Net Sales	92,693	142,881
Segment Operating Profit (Loss)	(10,824)	(2,402)
Segment Assets	54,516	58,377
Depreciation/Amortization	4,502	4,738
Expenditures for Long-Lived Assets	$ 267	$ 78