Treasury repurchase agreements and U.S. Treasury inflation-protected securities. See additional disclosure regarding the fair value of our cash equivalents and investments in Note 3. Included in the balance of other assets as of September 30, 2021 and December 31, 2020 was $5.0 million and $4.7 million, respectively, related to corporate-owned life insurance policies which are used to fund our deferred compensation plan. We determine the fair value of insurance contracts by obtaining the cash surrender value of the contracts from the issuer, a Level 2 valuation technique.
We have an investment in marketable securities, for which changes in fair value are recorded in the consolidated statement of operations as unrealized gain or (loss) on marketable securities, which is included in interest and other income (expense), net.
We have strategic investments in 3 unconsolidated affiliates. The estimated fair value of the investments was determined based on Level 3 inputs. As of September 30, 2021, management estimated that the fair value of the investments equaled the carrying value.
Our financial instruments also include accounts and notes receivable, accounts payable and accrued liabilities. Due to the short-term nature of these instruments, their fair values approximate their carrying values on the balance sheet.
Restricted Cash
Restricted cash balances as of September 30, 2021 and December 31, 2020 included $0.1 million primarily related to funds held in an international bank account for a country in which we are required to maintain a minimum balance to operate. Approximately half of the balance was included in prepaid expenses and other current assets on our condensed consolidated balance sheets, with the remainder included in other assets.
Valuation of Goodwill, Intangibles and Long-lived Assets
We evaluate whether events and circumstances have occurred that indicate the remaining estimated useful life of long-lived assets and identifiable intangible assets, excluding goodwill and intangible assets with indefinite useful lives, may warrant revision or that the remaining balance of these assets may not be recoverable. Such circumstances could include, but are not limited to, a change in the product mix, a change in the way products are created, produced or delivered, or a significant change in the way products are branded and marketed. In performing the review for recoverability, we estimate the future undiscounted cash flows expected to result from the use of the assets and their eventual disposition. The amount of the impairment loss, if impairment exists, is calculated based on the excess of the carrying amounts of the assets over their estimated fair value computed using discounted cash flows.
We do not amortize goodwill and intangible assets with indefinite useful lives; rather such assets are required to be tested for impairment at least annually or sooner whenever events or changes in circumstances indicate that the assets may be impaired. We perform our annual goodwill and intangible asset impairment tests in the fourth quarter of each year.
Recently Issued Accounting Guidance
Recently Adopted Accounting Pronouncements
In December 2019, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2019-12, Simplifying the Accounting for Income Taxes. Adoption of this ASU on January 1, 2021 did not have a material impact on our consolidated financial statements.
In January 2020, the FASB issued ASU No. 2020-01, Investments – Equity Securities (Topic 321), Investments – Equity Method and Joint Ventures (Topic 323), and Derivatives and Hedging (Topic 815) – Clarifying the Interactions Between Topic 321, Topic 323, and Topic 815 (a Consensus of the Emerging Issues Task Force). The guidance clarifies the interaction between ASU 2016-01, Financial Instruments – Overall (Subtopic 825-10): Recognition and Measurement