Revenue

9 Months Ended

Sep. 30, 2019

Revenue from Contract with Customer [Abstract]

Revenue from products or services provided to customers over time accounted for 33.4% and 26.8% of revenue for the three months ended September 30, 2019 and 2018, respectively, and 28.1% and 25.2% of revenue for the nine months ended September 30, 2019 and 2018, respectively. Revenue under these long-term agreements is generally recognized over time either using an input measure based upon the proportion of actual costs incurred to estimated total project costs or an input measure based upon actual labor costs as a percentage of estimated total labor costs, depending upon which measure the Company believes best depicts the Company’s performance to date under the terms of the contract. Revenue recognized over time using an input measure was $37,488 and $33,225 for the three months ended September 30, 2019 and 2018, respectively, and $104,309 and $87,369 for the nine months ended September 30, 2019 and 2018, respectively. A certain portion of the Company’s revenue recognized over time under these long-term agreements is recognized using an output method, specifically units delivered, based upon certain customer acceptance and delivery requirements. Revenue recognized over time using an output measure was $14,031 and $11,510 for the three months ended September 30, 2019 and 2018, respectively, and $37,553 and $29,064 for the nine months ended September 30, 2019 and 2018, respectively. As of September 30, 2019 and December 31, 2018, the Company had contract assets of $34,792 and $26,692, respectively, that were recorded in “Inventories - net” within the Condensed Consolidated Balance Sheets. As of September 30, 2019 and December 31, 2018, the Company had contract liabilities of $3,343 and $1,505, respectively, that were recorded in “Deferred revenue” within the Condensed Consolidated Balance Sheets.

The majority of the Company’s revenue is from products transferred and services rendered to customers at a point in time. Point in time revenue accounted for 66.6% and 73.2% of revenue for the three months ended September 30, 2019 and 2018, respectively, and 71.9% and 74.8% of revenue for the nine months ended September 30, 2019 and 2018, respectively. The Company recognizes revenue at the point in time at which the customer obtains control of the product or service, which is generally when the product title passes to the customer upon shipment or the service has been rendered to the customer. In limited cases, title does not transfer and revenue is not recognized until the customer has received the products at a physical location.

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,
	2019		2018		2019		2018
Rail Products	$	39,224	$	49,234	$	153,420	$	139,600
Rail Technologies	28,517		35,283		91,416		98,971
Rail Products and Services	67,741		84,517		244,836		238,571
Piling and Fabricated Bridge	28,703		26,798		90,023		71,505
Precast Concrete Products	18,472		14,736		49,903		41,136
Construction Products	47,175		41,534		139,926		112,641
Test, Inspection, and Threading Services	12,249		15,296		40,777		44,517
Protective Coatings and Measurement Systems	27,111		25,747		80,139		66,709
Tubular and Energy Services	39,360		41,043		120,916		111,226
Total net sales	$	154,276	$	167,094	$	505,678	$	462,438

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


	Three Months Ended September 30, 2019
	Rail Products and Services		Construction Products		Tubular and Energy Services		Total
Point in time	$	46,712	$	29,375	$	26,670	$	102,757
Over time	21,029		17,800		12,690		51,519
Total net sales	$	67,741	$	47,175	$	39,360	$	154,276

	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


	Nine Months Ended September 30, 2019
	Rail Products and Services		Construction Products		Tubular and Energy Services		Total
Point in time	$	183,905	$	90,565	$	89,346	$	363,816
Over time	60,931		49,361		31,570		141,862
Total net sales	$	244,836	$	139,926	$	120,916	$	505,678

	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

The timing of revenue recognition, billings, and cash collections results in billed receivables, costs in excess of billings (contract assets, included in “Inventories - net”), and billings in excess of costs (contract liabilities, included in “Deferred revenue”) on the Condensed Consolidated Balance Sheets.

Significant changes in contract assets during the nine months ended September 30, 2019 resulted from transfers to receivables from contract assets recognized at the beginning of the period of $22,320. Significant changes in contract liabilities during the nine months ended September 30, 2019 resulted from increases of $3,100 due to billings in excess of costs, excluding amounts recognized as revenue during the period. Contract liabilities were reduced due to revenue recognized during the three months ended September 30, 2019 and 2018 of $194 and $406, respectively, and reduced due to revenue recognized during the nine months ended September 30, 2019 and 2018 of $1,460 and $1,146, respectively, that were included in the contract liabilities at the beginning of each period.

As of September 30, 2019, the Company had approximately $194,083 of remaining performance obligations, which is also referred to as backlog. Approximately 7.7% of the September 30, 2019 backlog was related to projects that are anticipated to extend beyond September 30, 2020.