Revenue

6 Months Ended

Jun. 30, 2020

Revenue from Contract with Customer [Abstract]

Revenue

RevenueRevenue from products or services provided to customers over time accounted for 24.4% and 24.2% of revenue for the three months ended June 30, 2020 and 2019, respectively, and 24.9% and 25.7% of revenue for the six months ended June 30, 2020 and 2019, 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 $24,858 and $34,984 for the three months ended June 30, 2020 and 2019, respectively, and $49,290 and $66,821 for the six months ended June 30, 2020

and 2019, 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 $10,688 and $13,611 for the three months ended June 30, 2020 and 2019, respectively, and $19,033 and $23,522 for the six months ended June 30, 2020 and 2019, respectively. As of June 30, 2020 and December 31, 2019, the Company had contract assets of $33,606 and $37,032, respectively, that were recorded in “Inventories - net” within the Condensed Consolidated Balance Sheets. As of June 30, 2020 and December 31, 2019, the Company had contract liabilities of $4,967 and $4,472, 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 75.6% and 75.8% of revenue for the three months ended June 30, 2020 and 2019, respectively, and 75.1% and 74.3% of revenue for the six months ended June 30, 2020 and 2019, 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 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

	Six Months Ended June 30, 2020
	Rail Products and Services		Construction Products		Tubular and Energy Services		Total
Point in time	$	116,163	$	45,031	$	45,024	$	206,218
Over time	28,980		26,011		13,332		68,323
Total net sales	$	145,143	$	71,042	$	58,356	$	274,541
	Six Months Ended June 30, 2019
	Rail Products and Services		Construction Products		Tubular and Energy Services		Total
Point in time	$	137,193	$	61,190	$	62,676	$	261,059
Over time	39,902		31,561		18,880		90,343
Total net sales	$	177,095	$	92,751	$	81,556	$	351,402

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 six months ended June 30, 2020 resulted from transfers of $20,628 from the December 31, 2019 contract assets balance to receivables. Significant changes in contract liabilities during the six months ended June 30, 2020 resulted from increases of $2,751 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 June 30, 2020 and 2019 of $1,237 and $318, respectively, and reductions due to revenue recognized during the six months ended June 30, 2020 and 2019 of $3,851 and $1,266, respectively, which were included in the contract liabilities at the beginning of each period.

As of June 30, 2020, the Company had approximately $225,897 of remaining performance obligations, which is also referred to as backlog. Approximately 11.9% of the June 30, 2020 backlog was related to projects that are anticipated to extend beyond June 30, 2021.