Revenue

3 Months Ended

Mar. 31, 2021

Revenue from Contract with Customer [Abstract]

Revenue

RevenueRevenue from products or services provided to customers over time accounted for 25.3% and 26.9% of revenue for the three months ended March 31, 2021 and 2020, respectively. The majority of revenue under these long-term agreements is 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 $21,108 and $24,432 for the three months ended March 31, 2021 and 2020, 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 $8,264 and $8,345 for the three months ended March 31, 2021 and 2020, respectively. As of March 31, 2021 and December 31, 2020, the Company had contract assets of $37,673 and $37,843, respectively, that were recorded in “Inventories - net” within the Condensed

Consolidated Balance Sheets. As of March 31, 2021 and December 31, 2020, the Company had contract liabilities of $6,030 and $1,324, 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 74.7% and 73.1% of revenue for the three months ended March 31, 2021 and 2020, 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 for the periods presented:

	Three Months Ended March 31,
	2021		2020
Rail Products	$	43,810	$	47,899
Rail Technologies	22,422		22,305
Rail Technologies and Services	66,232		70,204
Fabricated Steel Products	27,721		18,391
Precast Concrete Products	12,678		10,643
Coatings and Measurement	9,449		22,669
Infrastructure Solutions	49,848		51,703
Total net sales	$	116,080	$	121,907

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

	Three Months Ended March 31, 2021
	Rail Technologies and Services		Infrastructure Solutions		Total
Point in time	$	52,044	$	34,664	$	86,708
Over time	14,188		15,184		29,372
Total net sales	$	66,232	$	49,848	$	116,080
	Three Months Ended March 31, 2020
	Rail Technologies and Services		Infrastructure Solutions		Total
Point in time	$	54,888	$	34,242	$	89,130
Over time	15,316		17,461		32,777
Total net sales	$	70,204	$	51,703	$	121,907

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”) within the Condensed Consolidated Balance Sheets.

Significant changes in contract assets during the three months ended March 31, 2021 resulted from transfers of $11,310 from the contract assets balance as of December 31, 2020 to receivables. Significant changes in contract liabilities during the three months ended March 31, 2021 resulted from increases of $5,425 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 March 31, 2021 and 2020 of $676 and $2,614, respectively, which were included in contract liabilities at the beginning of each period.

As of March 31, 2021, the Company had approximately $271,944 of obligations under new contracts and remaining performance obligations, which is also referred to as backlog. Approximately 13.0% of the March 31, 2021 backlog was related to projects that are anticipated to extend beyond March 31, 2022.