Business Segments (Assets by Segment) (Detail) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Assets	$ 470,016	$ 566,660
Rail Products and Services [Member]
Segment Reporting Information [Line Items]
Assets	199,217	241,222
Construction Products [Member]
Segment Reporting Information [Line Items]
Assets	90,382	86,335
Tubular and Energy Services [Member]
Segment Reporting Information [Line Items]
Assets	112,465	216,715
Unallocated Corporate Assets [Member]
Segment Reporting Information [Line Items]
Assets	$ 67,952	$ 22,388