Business Segments (Reconciliation of Significant Reconciling Items) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended										12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012		Jun. 30, 2012		Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Segment Reporting Information [Line Items]
Net sales	$ 156,458	$ 162,248	$ 149,936	$ 129,321	$ 140,724	$ 170,346	[1]	$ 163,180	[2]	$ 114,291	$ 597,963	$ 588,541	$ 575,337
Assets	413,654				406,122						413,654	406,122	379,894
Depreciation and amortization											10,002	12,973	12,007
Payments to Acquire Property, Plant, and Equipment											9,674	7,160	11,733
Rail Products Segment [Member]
Segment Reporting Information [Line Items]
Net sales											363,667	370,322	315,133
Segment Profit											28,692	9,074	18,724
Assets	252,049				243,072						252,049	243,072	219,917
Depreciation and amortization											6,505	9,736	8,908
Payments to Acquire Property, Plant, and Equipment											3,383	4,180	5,894
Construction Products Segment [Member]
Segment Reporting Information [Line Items]
Net sales											191,751	169,253	227,734
Segment Profit											10,206	7,859	16,323
Assets	77,900				73,804						77,900	73,804	88,615
Depreciation and amortization											1,758	2,119	2,180
Payments to Acquire Property, Plant, and Equipment											1,805	474	1,049
Tubular Products Segments [Member]
Segment Reporting Information [Line Items]
Net sales											42,545	48,966	32,470
Segment Profit											9,208	12,854	6,810
Assets	37,107				13,573						37,107	13,573	11,758
Depreciation and amortization											1,054	599	453
Payments to Acquire Property, Plant, and Equipment											2,460	1,350	3,995
Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales											597,963	588,541	575,337
Segment Profit											48,106	29,787	41,857
Assets	367,056				330,449						367,056	330,449	320,290
Depreciation and amortization											9,317	12,454	11,541
Payments to Acquire Property, Plant, and Equipment											$ 7,648	$ 6,004	$ 10,938

[1] Includes a pre-tax loss of approximately $315 from the Company’s sale of Precise.

[2] Includes a pre-tax gain of approximately $3,508 from the Company’s sale of SSD.