Description of Business and Summary of Significant Accounting Policies	9 Months Ended
Sep. 30, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business and Summary of Significant Accounting Policies	Description of Business and Summary of Significant Accounting Policies Description of Business TuSimple Holdings Inc. ("TuSimple" or the "Company") is a global autonomous driving technology company headquartered in San Diego, California, with operations in the United States ("U.S.") and Asia. Founded in 2015, TuSimple is developing a commercial-ready, fully autonomous (SAE Level 4) driving solution for long-haul heavy-duty trucks. Basis of Presentation and Consolidation The accompanying unaudited condensed consolidated financial statements (“Financial Statements”) have been prepared in accordance with accounting principles generally accepted in the U.S. (“GAAP”) and applicable rules and regulations of the Securities and Exchange Commission (“SEC”) regarding interim financial reporting. The Financial Statements include the accounts of the Company and its consolidated subsidiaries. All significant intercompany balances and transactions have been eliminated in consolidation. These Financial Statements should be read in conjunction with the audited consolidated financial statements and notes as of and for the year ended December 31, 2021, included in the Company's Annual Report on Form 10-K. The condensed consolidated balance sheet as of December 31, 2021 was derived from the audited consolidated financial statements as of that date, but does not include all disclosures required by GAAP. In management’s opinion, the accompanying Financial Statements reflect all normal recurring adjustments necessary for their fair presentation. Other than described below, there have been no changes to the Company’s significant accounting policies described in the Annual Report on Form 10-K for the year ended December 31, 2021 that have had a material impact on the Company’s Financial Statements. Cash, Cash Equivalents, and Restricted Cash Cash and cash equivalents consist of cash in banks and highly liquid investments, primarily money market funds, commercial paper and U.S. government and agency securities, purchased with an original maturity of three months or less. Restricted cash is pledged as security for letters of credit or other collateral amounts established by the Company for certain lease obligations, customer deposits, corporate credit cards, and other contractual arrangements. Restricted cash is recorded as prepaid expenses and other current assets in the condensed consolidated balance sheets based on the term of the remaining restriction. Concentration of Credit Risk Cash and cash equivalents and short-term investments are potentially subject to concentrations of credit risk. The Company's investment policy limits the amount of credit exposure with any one financial institution or commercial issuer and sets requirements regarding credit rating and investment maturities to safeguard liquidity and minimize risk. The majority of our cash deposits exceed insured limits and are placed with financial institutions around the world that the Company believes are of high credit quality. The Company has not experienced any material losses related to these concentrations during the periods presented. Fair Value Measurements Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The Company measures financial assets and liabilities at fair value at each reporting period using a fair value hierarchy which requires the Company to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. A financial instrument’s classification within the fair value hierarchy is based upon the lowest level of input that is significant to the fair value measurement. The levels of inputs used to measure fair value are: •Level 1 — Observable inputs such as quoted prices in active markets for identical assets or liabilities. •Level 2 — Observable inputs other than Level 1 prices such as quoted prices for similar assets or liabilities in active markets, quoted prices in markets that are not active or inputs other than the quoted prices that are observable either directly or indirectly for the full term of the assets or liabilities. •Level 3 — Unobservable inputs in which there is little or no market data that are significant to the fair value of the assets or liabilities. The Company’s primary financial instruments include cash equivalents, short-term investments, accounts receivable, accounts payable, amounts due to joint development partners, accrued expenses, short-term and long-term debt. The estimated fair value of these instruments approximates their carrying value due to their short-term nature. Refer to Note 2. Investments and Fair Value Measurements for further information. Investments Debt Securities Accounting for the Company's debt securities is based on the legal form of the security, the Company's intended holding period for the security, and the nature of the transaction. Investments in debt securities are classified as available-for-sale and are initially recorded at fair value. Investments in debt securities include commercial paper, U.S. treasury securities, U.S. government agency securities, and corporate debt securities. Subsequent changes in fair value of available-for-sale debt securities are recorded in other comprehensive income (loss), net of tax. Interest on these debt securities and amortization of premiums and accretion of discounts are included in interest income on the condensed consolidated statements of operations. The Company considers its debt securities as available for use in current operations, including those with maturity dates beyond one year, and therefore classifies these securities as short-term investments on the condensed consolidated balance sheets. The Company evaluates its available-for-sale debt securities to determine whether there is a decline in the fair value below its amortized cost basis (an impairment) at each reporting period. This evaluation consists of several qualitative and quantitative factors regarding the severity and duration of the unrealized loss as well as the Company’s ability and intent to hold the investment until a forecasted recovery occurs. Factors considered include: recent financial results and operating trends; implied values in recent transactions of investee securities; other publicly available information that may affect the value of the Company’s investments; severity and length of the decline in value; and the Company’s strategy and intentions for holding the investment. Impairment of the Company’s debt securities is recognized in earnings when a decline in value has occurred that is deemed to be other than temporary, and the current fair value becomes the new cost basis for the security. If the Company does not intend to sell a security and it is not more likely than not that it will be required to sell the security before recovery, the unrealized loss is separated into an amount representing the credit loss, which is recognized in earnings, and the amount related to all other factors, which is recorded in accumulated other comprehensive income (loss). Leases The Company accounts for leases in accordance with Accounting Standards Codification ("ASC") 842, Leases ("ASC 842"), which requires lessees to recognize on-balance sheet and disclose key information about leasing arrangements. The Company adopted ASC 842 along with all applicable ASU clarifications and improvements on January 1, 2022 using the modified retrospective transition method and used the effective date as the date of initial application. Consequently, financial information is not updated and disclosures required under ASC 842 are not provided for periods before January 1, 2022. ASC 842 provides a number of optional practical expedients in transition. The Company elected the "package of practical expedients," which permits the Company not to reassess under ASC 842 its prior conclusions about lease identification, lease classification and initial direct costs. The Company determines if a contract contains a lease based on whether it has the right to obtain substantially all of the economic benefits from the use of an identified asset and whether it has the right to direct the use of an identified asset in exchange for consideration, which relates to an asset which the Company does not own. Right-of-use (“ROU”) assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent the Company’s obligation to make lease payments arising from the lease. ROU assets are recognized as the lease liability, adjusted for lease incentives received. Lease liabilities are recognized at the present value of the future lease payments at the lease commencement date, net of lease incentive receivable. The interest rate used to determine the present value of the future lease payments is the Company’s incremental borrowing rate (“IBR”) because the interest rate implicit in most of the Company’s leases is not readily determinable. Lease payments may be fixed or variable, however, only fixed payments or in-substance fixed payments are included in the Company’s lease liability calculation. Variable lease payments are recognized in operating expenses in the period in which the obligation for those payments are incurred. The Company has lease agreements with lease and non-lease components and has elected to utilize the practical expedient to account for lease and non-lease components together as a single combined lease component. Additionally, the Company has determined that certain leases previously identified as build-to-suit leasing arrangements under legacy accounting, were derecognized pursuant to the transition guidance provided for build-to-suit leases in ASC 842. Accordingly, these leases have been reassessed as operating leases as of the adoption date under ASC 842, and are included on the condensed consolidated balance sheet as of September 30, 2022. The Company has leases that include one or more options to extend the lease term for up to five years and some of its leases include options to terminate the lease prior to the end of the agreed upon lease term. For purposes of calculating lease liabilities, lease terms include options to extend or terminate the lease when it is reasonably certain that the Company will exercise such options. Operating leases are included within operating lease ROU assets, operating lease liabilities, current, and operating lease liabilities, noncurrent on the Company's condensed consolidated balance sheet as of September 30, 2022. Finance leases are included in property and equipment, net, accrued expenses and other current liabilities, and other liabilities on the Company's condensed consolidated balance sheet as of September 30, 2022. The Company has elected not to present short-term leases on the consolidated balance sheet as these leases have a lease term of 12 months or less at lease inception and do not contain purchase options or renewal terms that the Company is reasonably certain to exercise. Adoption of the new lease standard on January 1, 2022 impacted the interim unaudited condensed consolidated financial statements as follows: (i) recognition of ROU assets of $32.9 million and lease liabilities of $35.1 million for operating leases, (ii) derecognition of build-to-suit lease assets and liabilities of $6.5 million and $4.4 million, respectively, with the net impact of $0.2 million recorded to accumulated deficit as of January 1, 2022, and (iii) reclassification of deferred rent and other liability balances of $2.5 million relating to its existing lease arrangements into the ROU asset balance as of January 1, 2022. The standard did not materially impact the condensed consolidated statement of operations and condensed consolidated statement of cash flows. Reclassifications Certain prior period balances have been reclassified to conform to the current period presentation in the condensed consolidated financial statements and the accompanying notes. Sales and marketing expense and general and administrative expense have been reclassified to selling, general and administrative expense. Interest income has been reclassified from other income (expense), net to interest income. Recently Adopted Accounting Pronouncements In February 2016, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2016-02, Leases, to require lessees to recognize all leases, with limited exceptions, on the balance sheet, while recognition on the statement of operations will remain similar to legacy lease accounting, ASC 840. Subsequently, the FASB issued ASU No. 2018-10, Codification Improvements to Topic 842, ASU No. 2018-11, Targeted Improvements, ASU No. 2018-20, Narrow-Scope Improvements for Lessors, and ASU 2019-01, Codification Improvements, to clarify and amend the guidance in ASU No. 2016-02. As disclosed above, the Company adopted the ASUs on January 1, 2022 on a modified retrospective basis. Recently Issued Accounting Pronouncements There have been no recent accounting pronouncements since the filing of the Company's Annual Report on Form 10-K for the year ended December 31, 2021, that may have a material impact on the Company's unaudited condensed consolidated financial statements.

TuSimple Holdings Inc. ("TuSimple" or the "Company") is a global autonomous driving technology company headquartered in San Diego, California, with operations in the United States ("U.S.") and Asia. Founded in 2015, TuSimple is developing a commercial-ready, fully autonomous (SAE Level 4) driving solution for long-haul heavy-duty trucks.

The accompanying unaudited condensed consolidated financial statements (“Financial Statements”) have been prepared in accordance with accounting principles generally accepted in the U.S. (“GAAP”) and applicable rules and regulations of the Securities and Exchange Commission (“SEC”) regarding interim financial reporting. The Financial Statements include the accounts of the Company and its consolidated subsidiaries. All significant intercompany balances and transactions have been eliminated in consolidation. These Financial Statements should be read in conjunction with the audited consolidated financial statements and notes as of and for the year ended December 31, 2021, included in the Company's Annual Report on Form 10-K.

The condensed consolidated balance sheet as of December 31, 2021 was derived from the audited consolidated financial statements as of that date, but does not include all disclosures required by GAAP. In management’s opinion, the accompanying Financial Statements reflect all normal recurring adjustments necessary for their fair presentation. Other than described below, there have been no changes to the Company’s significant accounting policies described in the Annual Report on Form 10-K for the year ended December 31, 2021 that have had a material impact on the Company’s Financial Statements.

Restricted cash is pledged as security for letters of credit or other collateral amounts established by the Company for certain lease obligations, customer deposits, corporate credit cards, and other contractual arrangements. Restricted cash is recorded as prepaid expenses and other current assets in the condensed consolidated balance sheets based on the term of the remaining restriction.

Cash and cash equivalents and short-term investments are potentially subject to concentrations of credit risk. The Company's investment policy limits the amount of credit exposure with any one financial institution or commercial issuer and sets requirements regarding credit rating and investment maturities to safeguard liquidity and minimize risk. The majority of our cash deposits exceed insured limits and are placed with financial institutions around the world that the Company believes are of high credit quality. The Company has not experienced any material losses related to these concentrations during the periods presented.

Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The Company measures financial assets and liabilities at fair value at each reporting period using a fair value hierarchy which requires the Company to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. A financial instrument’s classification within the fair value hierarchy is based upon the lowest level of input that is significant to the fair value measurement. The levels of inputs used to measure fair value are:

•Level 2 — Observable inputs other than Level 1 prices such as quoted prices for similar assets or liabilities in active markets, quoted prices in markets that are not active or inputs other than the quoted prices that are observable either directly or indirectly for the full term of the assets or liabilities.

The Company’s primary financial instruments include cash equivalents, short-term investments, accounts receivable, accounts payable, amounts due to joint development partners, accrued expenses, short-term and long-term debt. The estimated fair value of these instruments approximates their carrying value due to their short-term nature. Refer to Note 2. Investments and Fair Value Measurements for further information.

Accounting for the Company's debt securities is based on the legal form of the security, the Company's intended holding period for the security, and the nature of the transaction. Investments in debt securities are classified as available-for-sale and are initially recorded at fair value. Investments in debt securities include commercial paper, U.S. treasury securities, U.S. government agency securities, and corporate debt securities. Subsequent changes in fair value of available-for-sale debt securities are recorded in other comprehensive income (loss), net of tax. Interest on these debt securities and amortization of premiums and accretion of discounts are included in interest income on the condensed consolidated statements of operations. The Company considers its debt securities as available for use in current operations, including those with maturity dates beyond one year, and therefore classifies these securities as short-term investments on the condensed consolidated balance sheets.

The Company evaluates its available-for-sale debt securities to determine whether there is a decline in the fair value below its amortized cost basis (an impairment) at each reporting period. This evaluation consists of several qualitative and quantitative factors regarding the severity and duration of the unrealized loss as well as the Company’s ability and intent to hold the investment until a forecasted recovery occurs. Factors considered include: recent financial results and operating trends; implied values in recent transactions of investee securities; other publicly available information that may affect the value of the Company’s investments; severity and length of the decline in value; and the Company’s strategy and intentions for holding the investment.

Impairment of the Company’s debt securities is recognized in earnings when a decline in value has occurred that is deemed to be other than temporary, and the current fair value becomes the new cost basis for the security. If the Company does not intend to sell a security and it is not more likely than not that it will be required to sell the security before recovery, the unrealized loss is separated into an amount representing the credit loss, which is recognized in earnings, and the amount related to all other factors, which is recorded in accumulated other comprehensive income (loss).

The Company accounts for leases in accordance with Accounting Standards Codification ("ASC") 842, Leases ("ASC 842"), which requires lessees to recognize on-balance sheet and disclose key information about leasing arrangements. The Company adopted ASC 842 along with all applicable ASU clarifications and improvements on January 1, 2022 using the modified retrospective transition method and used the effective date as the date of initial application. Consequently, financial information is not updated and disclosures required under ASC 842 are not provided for periods before January 1, 2022. ASC 842 provides a number of optional practical expedients in transition. The Company elected the "package of practical expedients," which permits the Company not to reassess under ASC 842 its prior conclusions about lease identification, lease classification and initial direct costs.

The Company determines if a contract contains a lease based on whether it has the right to obtain substantially all of the economic benefits from the use of an identified asset and whether it has the right to direct the use of an identified asset in exchange for consideration, which relates to an asset which the Company does not own. Right-of-use (“ROU”) assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent the Company’s obligation to make lease payments arising from the lease. ROU assets are recognized as the lease liability, adjusted for lease incentives received. Lease liabilities are recognized at the present value of the future lease payments at the lease commencement date, net of lease incentive receivable. The interest rate used to determine the present value of the future lease payments is the Company’s incremental borrowing rate (“IBR”) because the interest rate implicit in most of the Company’s leases is not readily determinable. Lease payments may be fixed or variable, however, only fixed payments or in-substance fixed payments are included in the Company’s lease liability calculation. Variable lease payments are recognized in operating expenses in the period in which the obligation for those payments are incurred.

The Company has lease agreements with lease and non-lease components and has elected to utilize the practical expedient to account for lease and non-lease components together as a single combined lease component. Additionally, the Company has determined that certain leases previously identified as build-to-suit leasing arrangements under legacy accounting, were derecognized pursuant to the transition guidance provided for build-to-suit leases in ASC 842. Accordingly, these leases have been reassessed as operating leases as of the adoption date under ASC 842, and are included on the condensed consolidated balance sheet as of September 30, 2022.

The Company has leases that include one or more options to extend the lease term for up to five years and some of its leases include options to terminate the lease prior to the end of the agreed upon lease term. For purposes of calculating lease liabilities, lease terms include options to extend or terminate the lease when it is reasonably certain that the Company will exercise such options.

Operating leases are included within operating lease ROU assets, operating lease liabilities, current, and operating lease liabilities, noncurrent on the Company's condensed consolidated balance sheet as of September 30, 2022. Finance leases are included in property and equipment, net, accrued expenses and other current liabilities, and other liabilities on the Company's condensed consolidated balance sheet as of September 30, 2022.

The Company has elected not to present short-term leases on the consolidated balance sheet as these leases have a lease term of 12 months or less at lease inception and do not contain purchase options or renewal terms that the Company is reasonably certain to exercise.

Adoption of the new lease standard on January 1, 2022 impacted the interim unaudited condensed consolidated financial statements as follows: (i) recognition of ROU assets of $32.9 million and lease liabilities of $35.1 million for operating leases, (ii) derecognition of build-to-suit lease assets and liabilities of $6.5 million and $4.4 million, respectively, with the net impact of $0.2 million recorded to accumulated deficit as of January 1, 2022, and (iii) reclassification of deferred rent and other liability balances of $2.5 million relating to its existing lease arrangements into the ROU asset balance as of January 1, 2022. The standard did not materially impact the condensed consolidated statement of operations and condensed consolidated statement of cash flows.

Certain prior period balances have been reclassified to conform to the current period presentation in the condensed consolidated financial statements and the accompanying notes. Sales and marketing expense and general and administrative expense have been reclassified to selling, general and administrative expense. Interest income has been reclassified from other income (expense), net to interest income.

In February 2016, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2016-02, Leases, to require lessees to recognize all leases, with limited exceptions, on the balance sheet, while recognition on the statement of operations will remain similar to legacy lease accounting, ASC 840. Subsequently, the FASB issued ASU No. 2018-10, Codification Improvements to Topic 842, ASU No. 2018-11, Targeted Improvements, ASU No. 2018-20, Narrow-Scope Improvements for Lessors, and ASU 2019-01, Codification Improvements, to clarify and amend the guidance in ASU No. 2016-02. As disclosed above, the Company adopted the ASUs on January 1, 2022 on a modified retrospective basis.