Business Segments (Schedule Of Reporting Sement Data To Consolidated Totals From Continuing Ops) (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
Income (Loss) from Equity Method Investments											1,316	837	707
Income (loss) from continuing operations, before income taxes											44,115	23,830	32,652
Assets	413,654				406,122						413,654	406,122	379,894
Depreciation and amortization											10,002	12,973	12,007
Capital expenditures on property, plant and equipment											9,674	7,160	11,733
Long-lived assets of continuing operating activities	50,109				42,333						50,109	42,333	45,837
Rail distribution products [Member]
Segment Reporting Information [Line Items]
Net sales											144,911	155,832	115,777
Piling Products [Member]
Segment Reporting Information [Line Items]
Net sales											140,302	114,070	162,641
Rail Technologies products [Member]
Segment Reporting Information [Line Items]
Net sales											88,670	92,826	97,775
CXT concrete tie products [Member]
Segment Reporting Information [Line Items]
Net sales											44,108	58,182	48,968
Transit Products [Member]
Segment Reporting Information [Line Items]
Net sales											41,947	22,215	17,256
CXT concrete building products [Member]
Segment Reporting Information [Line Items]
Net sales											32,969	30,195	35,557
Other products [Member]
Segment Reporting Information [Line Items]
Net sales											105,056	115,221	97,363
United States [Member]
Segment Reporting Information [Line Items]
Net sales											495,710	485,111	483,889
Long-lived assets of continuing operating activities	40,717				31,961						40,717	31,961	35,918
Canada [Member]
Segment Reporting Information [Line Items]
Net sales											37,290	40,892	41,252
Long-lived assets of continuing operating activities	8,833				9,773						8,833	9,773	9,374
United Kingdom [Member]
Segment Reporting Information [Line Items]
Net sales											16,548	18,698	14,728
Long-lived assets of continuing operating activities	559				599						559	599	545
Other - Seg Reporting [Member]
Segment Reporting Information [Line Items]
Net sales											48,415	43,840	35,468
Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales											597,963	588,541	575,337
Operating Income (Loss)											48,106	29,787	41,857
Income (loss) from continuing operations, before income taxes											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
Capital expenditures on property, plant and equipment											7,648	6,004	10,938
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Interest Income, Other											659	452	321
Income (Loss) from Equity Method Investments											1,316	837	707
Unallocated Corporate Costs and Expenses											(6,003)	(8,364)	(8,050)
Assets	55,625				84,737						55,625	84,737	69,787
Depreciation and amortization											685	519	466
Capital expenditures on property, plant and equipment											2,026	1,156	795
Segment Reconciling Items, LIFO [Member]
Segment Reporting Information [Line Items]
Inventory, LIFO Reserve, Effect on Income, Net											37	1,118	(2,183)
Assets	$ (9,027)				$ (9,064)						$ (9,027)	$ (9,064)	$ (10,183)

[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.