Contract Assets and Liabilities

6 Months Ended

Jun. 30, 2020

Revenue from Contract with Customer [Abstract]

Contract Assets and Liabilities

Revenue

We disaggregate our revenue from customers by type of service and by geographic region as we believe it best depicts how the nature, amount, timing and uncertainty of our revenue and cash flows are affected by economic factors. See details in the tables below.

	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2020		2019		2020		2019
Environmental Solutions
Product sales	$	21,400	$	24,890	$	43,161	$	47,402
Construction contracts	15,347		11,900		30,194		46,207
Services	1,115		160		1,172		1,724
Total Environmental Solutions	37,862		36,950		74,527		95,333
Maintenance and Technical Services
Services	95,283		83,986		223,249		188,861
Total Maintenance and Technical Services	95,283		83,986		223,249		188,861
Total revenue	$	133,145	$	120,936	$	297,776	$	284,194

	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2020		2019		2020		2019
Environmental Solutions
United States	$	37,651	$	36,950	$	73,681	$	95,333
Foreign	211		—		846		—
Total Environmental Solutions	37,862		36,950		74,527		95,333
Maintenance and Technical Services
United States	95,283		83,986		223,249		188,861
Total Maintenance and Technical Services	95,283		83,986		223,249		188,861
Total revenue	$	133,145	$	120,936	$	297,776	$	284,194

As of June 30, 2020, the Company had remaining performance obligations with an aggregate transactions price of $125,266 on construction contracts for which we recognize revenue over time. We expect to recognize approximately 35% of our remaining performance obligations as revenue during the remainder of 2020, 29% in 2021, 10% in 2022, and 26% thereafter. Revenue associated with our remaining performance obligations includes performance obligations related to our construction contracts. The balance of remaining performance obligations does not include variable consideration that was determined to be constrained as of June 30, 2020. As of June 30, 2020, we included unapproved change orders associated with project scope changes of $1,655 included in determining the profit or loss on certain construction contracts.

Contract Assets and Liabilities

The timing of revenue recognition, billings and cash collections results in accounts receivable, contract assets, and contract liabilities on the unaudited condensed consolidated balance sheets.

Our contract assets are as follows:

	June 30, 2020		December 31, 2019
Costs and estimated earnings in excess of billings	$	15,968	$	19,256
Retainage	3,765		1,385
Total contract assets	$	19,733	$	20,641

Our contract liabilities are as follows:

	June 30, 2020		December 31, 2019
Deferred revenue	$	465	$	505
Billings in excess of costs and estimated earnings	14,490		77
Total contract liabilities	$	14,955	$	582

We recognized revenue of $163 and $423 for the three and six months ended June 30, 2020, respectively, that was previously included in contract liabilities at December 31, 2019. The increase in contract liabilities was primarily due to an increase in billings in excess of costs and estimated earnings associated with billings during the three months ended June 30, 2020 for a specific remediation and compliance project.

Costs and estimated earnings on uncompleted contracts are as follows:

	June 30, 2020			December 31, 2019
Costs incurred on uncompleted contracts	$	91,513		$	65,343
Estimated earnings	12,827			9,618
Total costs and estimated earnings	104,340			74,961
Less billings to date	(102,862		)	(55,782		)
Costs and estimated earnings in excess of billings	$	1,478		$	19,179

The net balance in process classified on the unaudited condensed consolidated balance sheets is as follows: 

	June 30, 2020			December 31, 2019
Costs and estimated earnings in excess of billings	$	15,968		$	19,256
Billings in excess of costs and estimated earnings	(14,490		)	(77		)
Net balance in process	$	1,478		$	19,179

Anticipated losses on long-term contracts are recognized when such losses become evident. As of June 30, 2020 and December 31, 2019, accruals for anticipated losses on long-term contracts were $251 and $322, respectively.