Business Segments - Reconciliation of Assets from Segment to Consolidated (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Segment Reporting Information
Assets	$ 378,930	$ 405,171
Operating Segments | Rail Products and Services
Segment Reporting Information
Assets	168,318	186,323
Operating Segments | Construction Products
Segment Reporting Information
Assets	97,170	83,049
Operating Segments | Tubular and Energy Services
Segment Reporting Information
Assets	42,501	47,638
Unallocated corporate and discontinued operations assets
Segment Reporting Information
Assets	$ 70,941	$ 88,161