Business Segments - Reconciliation of Assets from Segment to Consolidated (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Segment Reporting Information
Assets	$ 326,401	$ 313,206
Operating Segments | Rail, Technologies, and Services
Segment Reporting Information
Assets	167,565	157,023
Operating Segments | Infrastructure Solutions
Segment Reporting Information
Assets	129,852	130,667
Unallocated corporate assets
Segment Reporting Information
Assets	$ 28,984	$ 25,516