Business Segments - Reconciliation of Assets from Segment to Consolidated (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Segment Reporting Information
Assets	$ 334,591	$ 365,310
Operating Segments | Rail, Technologies, and Services
Segment Reporting Information
Assets	164,728	172,111
Operating Segments | Precast Concrete Products
Segment Reporting Information
Assets	106,243	108,598
Operating Segments | Steel Products and Measurement
Segment Reporting Information
Assets	36,481	54,516
Unallocated corporate assets
Segment Reporting Information
Assets	$ 27,139	$ 30,085