NOTE 5. REVENUE FROM CONTRACTS WITH CUSTOMERS

We believe that disaggregating our revenue by reportable segment in "Note 12. Business Segments" provides the information necessary to understand the nature, amount, timing and uncertainty of our revenues and cash flows.

Contract Balances with Customers

Our contract assets are included in “Accounts receivable” in our unaudited condensed consolidated balance sheets. Accounts receivable consist of invoiced amounts or amounts for which we have a right to invoice based on services completed or products delivered.

Our current and non-current contract liabilities are included in “Other current liabilities” and “Other liabilities,” respectively, in our unaudited condensed consolidated balance sheets. Our contract liabilities consist of deferred revenues from advance consideration received from customers related to future performance of service or delivery of products and off-market contract liabilities from unfavorable contracts recognized in connection with our business acquisitions in the Proppant Production segment.

In the accounting for prior business combinations, we recorded off-market contract liabilities. During the three and nine months ended September 30, 2024, we recorded amortization of $8.9 million and $36.1 million, respectively, related to these contract liabilities as revenue compared with $16.4 million and $41.0 million in the respective periods last year. As of September 30, 2024 and December 31, 2023, our off-market contract liabilities amounted to $15.0 million and $51.1 million, respectively. Estimated future amortization of off-market contract liabilities to revenue is $7.4 million for the remainder of 2024 and $7.6 million in 2025.

Performance Obligations

Certain of our Proppant Production contracts contain multiple performance obligations to provide a minimum quantity of proppant products to our customers in future periods. For these contracts, the transaction price is allocated to each performance obligation at estimated selling prices and we recognize revenue as we satisfy these performance obligations. As of September 30, 2024, the aggregate amount of transaction price allocated to unsatisfied performance obligations was $135.1 million, and we expect to perform these obligations and recognize revenue of $6.3 million for the remainder of 2024, $68.8 million in 2025, $45.0 million in 2026, and $15.0 million in 2027.

We have elected the practical expedient permitting the exclusion of disclosing the value of unsatisfied performance obligations for Stimulation Services and Manufacturing contracts as these contracts have original contract terms of one year or less or we have the right to invoice for services performed.