Business Segments (Reconciliation of Significant Reconciling Items) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
Segment Reporting Information [Line Items]
Net sales	$ 166,832	$ 149,936	$ 278,246	$ 279,257
Segment Profit	12,933	12,438	20,051	21,708
Assets	439,952		439,952		413,654
Depreciation and amortization			5,988	4,741
Payments to Acquire Property, Plant, and Equipment			7,682	3,126
Rail Products Segment [Member]
Segment Reporting Information [Line Items]
Net sales	107,484	90,892	180,980	172,291
Segment Profit	6,836	5,835	12,152	12,036
Construction Products Segment [Member]
Segment Reporting Information [Line Items]
Net sales	41,810	43,697	69,193	80,508
Segment Profit	3,371	2,056	4,587	2,518
Tubular Products Segments [Member]
Segment Reporting Information [Line Items]
Net sales	17,538	15,347	28,073	26,458
Segment Profit	$ 2,726	$ 4,547	$ 3,312	$ 7,154