Business Segments (Reconciliation of Significant Reconciling Items) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015		Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Net sales	$ 624,523		$ 607,192	$ 597,963
Assets	566,660		491,717	413,193
Depreciation and amortization	26,674		12,577	10,002
Expenditures for Long-Lived Assets	15,201		19,037	9,674
Rail Products and Services [Member]
Segment Reporting Information [Line Items]
Net sales	328,982		374,615	363,667
Segment Profit (Loss)	27,037		30,093	28,692
Assets	241,222		239,951	252,049
Depreciation and amortization	8,098		6,153	6,505
Expenditures for Long-Lived Assets	4,273		5,115	3,383
Construction Products [Member]
Segment Reporting Information [Line Items]
Net sales	176,394		178,847	191,751
Segment Profit (Loss)	12,958		13,106	10,206
Assets	86,335		102,978	77,900
Depreciation and amortization	2,720		2,232	1,758
Expenditures for Long-Lived Assets	1,260		3,343	1,805
Tubular and Energy Services [Member]
Segment Reporting Information [Line Items]
Net sales	119,147		53,730	42,545
Segment Profit (Loss)	(81,344)	[1]	5,350	9,208
Assets	216,715		130,289	51,497
Depreciation and amortization	14,857		3,208	1,054
Expenditures for Long-Lived Assets	4,303		6,988	2,460
Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	624,523		607,192	597,963
Segment Profit (Loss)	(41,349)		48,549	48,106
Assets	544,272		473,218	381,446
Depreciation and amortization	25,675		11,593	9,317
Expenditures for Long-Lived Assets	$ 9,836		$ 15,446	$ 7,648

[1] Segment loss includes impairment of goodwill as further described in Note 4.