Business Segments (Reconciliation of Significant Reconciling Items) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Segment Reporting Information [Line Items]
Net sales	$ 137,907	$ 111,414
Segment Profit	9,258	7,118
Rail Products and Services Segment [Member]
Segment Reporting Information [Line Items]
Net sales	77,676	73,496
Segment Profit	6,072	5,316
Construction Products Segment [Member]
Segment Reporting Information [Line Items]
Net sales	34,290	27,383
Segment Profit	1,228	1,216
Tubular and Energy Services Segments [Member]
Segment Reporting Information [Line Items]
Net sales	25,941	10,535
Segment Profit	$ 1,958	$ 586