Business Segments - Reconciliation of Assets from Segment to Consolidated (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Segment Reporting Information
Assets	$ 336,378	$ 365,310
Operating Segments | Rail, Technologies, and Services
Segment Reporting Information
Assets	163,001	172,111
Operating Segments | Precast Concrete Products
Segment Reporting Information
Assets	104,581	108,598
Operating Segments | Steel Products and Measurement
Segment Reporting Information
Assets	38,236	54,516
Unallocated corporate assets
Segment Reporting Information
Assets	$ 30,560	$ 30,085