Business Segments (Reconciliation of Significant Reconciling Items) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Segment Reporting Information [Line Items]
Net sales	$ 171,419	$ 166,832	$ 309,326	$ 278,246
Segment Profit	11,929	12,933	21,187	20,051
Rail Products and Services [Member]
Segment Reporting Information [Line Items]
Net sales	86,882	107,484	164,558	180,980
Segment Profit	6,413	6,836	12,485	12,152
Construction Products Segment [Member]
Segment Reporting Information [Line Items]
Net sales	49,516	41,810	83,806	69,193
Segment Profit	5,158	3,371	6,386	4,587
Tubular and Energy Services [Member]
Segment Reporting Information [Line Items]
Net sales	35,021	17,538	60,962	28,073
Segment Profit	$ 358	$ 2,726	$ 2,316	$ 3,312