Performance Obligations
As of September 30, 2020, we had $387.6 million of remaining performance obligations related to our contract operations segment. We do not consider the effects of the time value of money, as the expected time between the transfer of services and payment for such services is less than one year. Our remaining performance obligations will be recognized through 2025 as follows (in thousands):
| | | | | | | | | | | | | | | | | | | | | |
| | 2020 | | 2021 | | 2022 | | 2023 | | 2024 | | 2025 | | Total |
Remaining performance obligations | | $ | 105,933 | | $ | 195,902 | | $ | 74,732 | | $ | 9,694 | | $ | 1,196 | | $ | 116 | | $ | 387,573 |
We do not disclose the aggregate transaction price for the remaining performance obligations for aftermarket services as there are no contracts with customers with an original contract term that is greater than one year.
Contract Assets and Liabilities
As of September 30, 2020 and December 31, 2019, our receivables from contracts with customers, net of allowance for credit losses, were $102.8 million and $139.4 million, respectively.
Freight billings to customers for the transport of compression assets, customer-specified modifications of compression assets and milestone billings on aftermarket services often result in a contract liability. As of September 30, 2020 and December 31, 2019, our contract liabilities were $4.9 million and $11.4 million, respectively, which were included in deferred revenue and other liabilities in our condensed consolidated balance sheets. The decrease in the contract liability balance during the nine months ended September 30, 2020 was primarily due to $17.2 million recognized as revenue during the period, partially offset by revenue deferral of $10.7 million, each primarily related to freight billings and milestone billings on aftermarket services.
13. Long-Lived and Other Asset Impairment
We review long-lived assets, including property, plant and equipment and identifiable intangibles that are being amortized, for impairment whenever events or changes in circumstances, including the removal of compressors from our active fleet, indicate that the carrying amount of an asset may not be recoverable.
In the first quarter of 2020, we determined that the impairment of our contract operations reporting unit’s goodwill was an indicator of potential impairment of the carrying amount of our long-lived assets, including our compressor fleet and associated customer and contract-based intangible assets. Accordingly, we performed a quantitative impairment test of our long-lived assets, by which we determined that they were not also impaired. No similar impairment has been indicated subsequent to the first quarter.
Compression Fleet
We periodically review the future deployment of our idle compression assets for units that are not of the type, configuration, condition, make or model that are cost efficient to maintain and operate. Based on these reviews, we determine that certain idle compressors should be retired from the active fleet. The retirement of these units from the active fleet triggers a review of these assets for impairment and as a result of our review, we may record an asset impairment to reduce the book value of each unit to its estimated fair value. The fair value of each unit is estimated based on the expected net sale proceeds compared to other fleet units we recently sold, a review of other units recently offered for sale by third parties or the estimated component value of the equipment we plan to use.
In connection with our review of our idle compression assets, we evaluate for impairment idle units that were culled from our fleet in prior years and are available for sale. Based on that review, we may reduce the expected proceeds from disposition and record additional impairment to reduce the book value of each unit to its estimated fair value.