Revenue (Tables)

12 Months Ended

Dec. 31, 2018

Revenue from Contract with Customer [Abstract]

Disaggregation of Revenue

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

	Year Ended December 31,
	2018		2017
Rail Products	$	188,590	$	155,870
Rail Technologies	130,934		100,257
Rail Products and Services	319,524		256,127
Piling and Fabricated Bridge Products	102,246		105,924
Precast Concrete Products	56,407		55,877
Construction Products	158,653		161,801
Test, Inspection, and Threading Services	59,766		50,683
Protective Coatings and Measurement Systems	89,026		67,766
Tubular and Energy Services	148,792		118,449
Total net sales	$	626,969	$	536,377

Net sales by the timing of the transfer of goods and services is as follows:

Year Ended December 31, 2018	Rail Products and Services		Construction Products		Tubular and Energy Services		Total
Point in time	$	232,814	$	106,168	$	124,734	$	463,716
Over time	86,710		52,485		24,058		163,253
Total net sales	$	319,524	$	158,653	$	148,792	$	626,969
Year Ended December 31, 2017	Rail Products and Services		Construction Products		Tubular and Energy Services		Total
Point in time	$	205,942	$	97,462	$	99,635	$	403,039
Over time	50,185		64,339		18,814		133,338
Total net sales	$	256,127	$	161,801	$	118,449	$	536,377