Revenue (Tables)

6 Months Ended

Jun. 30, 2020

Revenue from Contract with Customer [Abstract]

Disaggregation of Revenue

The following table summarizes the Company's net sales by major product and service category:

	Three Months Ended June 30,				Six Months Ended June 30,
	2020		2019		2020		2019
Rail Products	$	52,206	$	67,990	$	95,768	$	114,196
Rail Technologies	22,733		33,411		49,375		62,899
Rail Products and Services	74,939		101,401		145,143		177,095
Piling and Fabricated Bridge	25,580		37,588		43,971		61,320
Precast Concrete Products	16,428		17,818		27,071		31,431
Construction Products	42,008		55,406		71,042		92,751
Test, Inspection, and Threading Services	8,673		13,804		18,377		28,528
Protective Coatings and Measurement Systems	20,146		30,322		39,979		53,028
Tubular and Energy Services	28,819		44,126		58,356		81,556
Total net sales	$	145,766	$	200,933	$	274,541	$	351,402

Net sales by the timing of the transfer of products and services was as follows:

	Three Months Ended June 30, 2020
	Rail Products and Services		Construction Products		Tubular and Energy Services		Total
Point in time	$	61,275	$	28,148	$	20,797	$	110,220
Over time	13,664		13,860		8,022		35,546
Total net sales	$	74,939	$	42,008	$	28,819	$	145,766
	Three Months Ended June 30, 2019
	Rail Products and Services		Construction Products		Tubular and Energy Services		Total
Point in time	$	80,701	$	38,095	$	33,542	$	152,338
Over time	20,700		17,311		10,584		48,595
Total net sales	$	101,401	$	55,406	$	44,126	$	200,933