Revenue (Tables)

9 Months Ended

Sep. 30, 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:

	Three Months Ended September 30,				Nine Months Ended September 30,
	2018		2017		2018		2017
Rail Products	$	49,234	$	36,297	$	139,600	$	115,061
Rail Technologies	35,283		25,798		98,971		72,861
Rail Products and Services	84,517		62,095		238,571		187,922
Piling and Fabricated Bridge	26,798		24,186		71,505		83,016
Precast Concrete Products	14,736		14,932		41,136		38,889
Construction Products	41,534		39,118		112,641		121,905
Test, Inspection, and Threading	15,296		13,729		44,517		37,661
Protective Coatings and Measurement Solutions	25,747		16,550		66,709		47,566
Tubular and Energy Services	41,043		30,279		111,226		85,227
Total net sales	$	167,094	$	131,492	$	462,438	$	395,054

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

Three Months Ended September 30, 2018	Rail Products and Services		Construction Products		Tubular and Energy Services		Total
Point in time	$	61,426	$	27,459	$	33,474	$	122,359
Over time	23,091		14,075		7,569		44,735
Total net sales	$	84,517	$	41,534	$	41,043	$	167,094
Three Months Ended September 30, 2017	Rail Products and Services		Construction Products		Tubular and Energy Services		Total
Point in time	$	51,043	$	22,768	$	26,138	$	99,949
Over time	11,052		16,350		4,141		31,543
Total net sales	$	62,095	$	39,118	$	30,279	$	131,492

Nine Months Ended September 30, 2018	Rail Products and Services		Construction Products		Tubular and Energy Services		Total
Point in time	$	176,592	$	74,581	$	94,832	$	346,005
Over time	61,979		38,060		16,394		116,433
Total net sales	$	238,571	$	112,641	$	111,226	$	462,438
Nine Months Ended September 30, 2017	Rail Products and Services		Construction Products		Tubular and Energy Services		Total
Point in time	$	153,707	$	76,158	$	73,189	$	303,054
Over time	34,215		45,747		12,038		92,000
Total net sales	$	187,922	$	121,905	$	85,227	$	395,054