Business Segments - Reconciliation of Assets from Segment to Consolidated (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Segment Reporting Information
Assets	$ 351,568	$ 365,310
Operating Segments | Rail, Technologies, and Services
Segment Reporting Information
Assets	177,515	172,111
Operating Segments | Precast Concrete Products
Segment Reporting Information
Assets	104,892	108,598
Operating Segments | Steel Products and Measurement
Segment Reporting Information
Assets	38,492	54,516
Unallocated corporate assets
Segment Reporting Information
Assets	$ 30,669	$ 30,085