Basis of Presentation, Use of Estimates and Recent Accounting Pronouncements	3 Months Ended
Mar. 31, 2019
Accounting Policies [Abstract]
Basis of Presentation, Use of Estimates and Recent Accounting Pronouncements	2. Basis of Presentation, Use of Estimates and Recent Accounting Pronouncements Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles, or U.S. GAAP, and follow the requirements of the Securities and Exchange Commission, or the SEC, for interim reporting. As permitted under those rules, certain footnotes or other financial information that are normally required by U.S. GAAP have been condensed or omitted, and accordingly the balance sheet as of December 31, 2018 has been derived from audited consolidated financial statements at that date but does not include all of the information required by U.S. GAAP for complete financial statements. These financial statements have been prepared on the same basis as the Company’s annual financial statements and, in the opinion of management, reflect all adjustments (consisting only of normal recurring adjustments) that are necessary for a fair presentation of the Company’s financial information. The results of operations for the three months ended March 31, 2019 are not necessarily indicative of the results to be expected for the year ending December 31, 2019 or for any other interim period or for any other future year. The accompanying condensed consolidated financial statements and related financial information should be read in conjunction with the audited consolidated financial statements and the related notes thereto for the year ended December 31, 2018 included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2018 filed with the SEC on February 27, 2019. The condensed consolidated financial statements include the accounts of Aduro Biotech, Inc. and its wholly-owned subsidiaries. All intercompany transactions and balances have been eliminated. Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities and reported amounts of revenue and expenses in the financial statements and accompanying notes. On an ongoing basis, management evaluates its estimates, including those related to revenue recognition, clinical trial accruals, contingent consideration, income taxes, right-of-use asset, lease obligation, and stock-based compensation. Management bases its estimates on historical experience and on various other market-specific and relevant assumptions that management believes to be reasonable under the circumstances. Actual results could differ from these estimates. Leases On January 1, 2019, the Company adopted the new standard on leases, Accounting Standard Codification 842, which establishes a comprehensive new lease accounting model. The following steps were taken to be consistent with the guidance in accounting for leases under the new standard. The Company determines if an arrangement is a lease at inception. The Company elected the practical expedient to adopt the policy to not separate lease and non-lease components. Operating leases are included in operating lease right-of-use assets, ROU, and operating lease liabilities on the Company’s consolidated balance sheets. Operating lease ROU assets represent the Company’s right to use an underlying asset for the lease term and operating lease liabilities represent the Company’s obligation to make lease payments arising from the lease. Operating lease ROU assets and operating lease liabilities are recognized based on the present value of lease payments over the lease term. As most of the Company’s leases do not provide an implicit rate, the Company uses its incremental borrowing rate in determining the present value of lease payments. The operating lease ROU asset also includes any lease payments made and excludes lease incentives. The Company’s lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise such options to extend or terminate the lease. Lease expense for lease payments is recognized on a straight-line basis over the lease term. Stock-Based Compensation On January 1, 2019, the Company adopted Accounting Standard Update 2018-07, simplifying its accounting for share-based payments to non-employees by aligning it with the accounting for share-based payments to employees, with certain exceptions. The Company measured its stock-based awards made to non-employees based on the estimated fair values of the awards as of the adoption date of January 1, 2019 using the Black-Scholes option-pricing model. Stock-based compensation expense is recognized over the remaining requisite service period using the straight-line method and is based on the value of the portion of stock-based payment awards that is ultimately expected to vest. As such, the Company’s stock-based compensation is reduced for the estimated forfeitures and revised, if necessary, in subsequent periods if actual forfeitures differ from the original estimates. Recent Accounting Pronouncements In June 2016, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update, or ASU, No. 2016-13, Financial Instruments—Credit Losses (Topic 326). The standard changes how entities will measure credit losses for most financial assets and certain other instruments that are not measured at fair value through net income. Financial assets measured at amortized cost will be presented at the net amount expected to be collected by using an allowance for credit losses. The standard is effective for fiscal years and interim periods beginning after December 15, 2019. Early adoption is permitted for all periods beginning after December 15, 2018. The Company has evaluated the impact of this guidance and has concluded that adoption of the standard will not have a material impact on its condensed consolidated financial statements. In August 2018, the FASB issued ASU No. 2018-13 – Fair Value Measurement (Topic 820): Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement. The standard eliminates certain disclosure requirements for fair value measurements for all entities, requires public entities to disclose certain new information, and modifies some disclosure requirements. The new standard is effective for fiscal years and interim periods beginning after December 15, 2019. Early adoption is permitted upon issuance of this ASU. Entities making this election to early adopt are permitted to early adopt the eliminated or modified disclosure requirements and delay the adoption of the new disclosure requirements until their effective date. The Company is currently evaluating the impact that the standard will have on its condensed consolidated financial statements. Recently Adopted Accounting Pronouncements In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) (ASC 842), which establishes a comprehensive new lease accounting model. The new standard: (a) clarifies the definition of a lease; (b) requires a dual approach to lease classification similar to current lease classifications; and (c) causes lessees to recognize leases on the balance sheet as a lease liability with a corresponding ROU asset for leases with a lease-term of more than twelve months. The new standard is effective for fiscal years and interim periods beginning after December 15, 2018, with early adoption permitted. A modified retrospective transition approach is required for leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements. In July 2018, the FASB issued ASU No. 2018-11, Leases (Topic 842): Targeted Improvements, an update which provides another transition method, the prospective transition method, which allows entities to initially apply the new lease standard at the adoption date and recognize a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption. The Company adopted the new standard on January 1, 2019 using the prospective transition method. The Company identified all leases and reviewed the leases to determine the impact of ASC 842 on its condensed consolidated financial statements. The Company has elected to apply all of the practical expedients as a package, which include not reassessing (1) whether any expired or existing contracts are or contain leases, (2) lease classification for any expired or existing leases, and (3) initial direct costs for any existing leases. The Company also elected the practical expedient to not separate lease and non-lease components for its real estate leases. Based on the Company’s assessment, the Company concluded that the adoption of the new standard resulted in the recording of a $22.1 million ROU asset and a $33.8 million lease liability and a derecognition of $11.7 million of deferred rent on the consolidated balance sheet on January 1, 2019. The Company’s adoption of ASU 2016-02, as amended, did not have a material impact on its condensed consolidated statements of operations or condensed consolidated statements of cash flows. In February 2018, the FASB issued ASU No. 2018-02, Income Statement-Reporting Comprehensive Income (Topic 220). The standard update allows for a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the Tax Cuts and Jobs Act of 2017, or the Tax Act. Consequently, the ASU 2018-02 eliminates the stranded tax effects resulting from the Tax Act. The new standard is effective for fiscal years and interim periods beginning after December 15, 2018. Early adoption is permitted, including adoption in any interim period for reporting periods for which financial statements have not yet been issued. The new standard should be applied either in the period of adoption or retrospectively to each period (or periods) in which the effect of the change in the U.S. federal corporate income tax rate in the Tax Act is recognized. The Company adopted the new standard on January 1, 2019 and due to the full valuation allowance, the Company concluded that there is no impact on its condensed consolidated financial statements. In June 2018, the FASB issued ASU No. 2018-07 – Compensation-Stock Compensation (Topic 718): Improvements to Non-employee Shared-Based Payment Accounting. The standard update expands the scope of Topic 718 to include share-based payment transactions for acquiring goods and services from non-employees. The new standard simplifies several aspects of Topic 718 by expanding the scope of the following areas to account for non-employee shared-based payment transactions: (1) overall measurement objective, (2) measurement date, (3) awards with performance conditions, and (4) classification reassessment of certain equity-classified awards. The new standard is effective for fiscal years and interim periods beginning after December 15, 2018. Early adoption is permitted, but no earlier than an entity’s adoption date of Topic 606. The Company adopted the new standard on January 1, 2019. As a result, existing non-employee awards were measured as of the adoption date and the related expense will be recognized over the remaining requisite service period using the straight-line method. New awards made to non-employees will be measured at the grant date. In November 2018, the FASB issued ASU No. 2018-18 – Collaborative Arrangements (Topic 808): Clarifying the Interaction between Topic 808 and Topic 606. The standard update requires transactions in collaborative arrangements to be accounted for under Topic 606, if the counterparty is a customer for a good or service that is a distinct unit of account. The standard update also precludes entities from presenting consideration from transactions with a collaborator that is not a customer together with revenue recognized from contracts with customers. The new standard is effective for fiscal years and interim periods beginning after December 15, 2019. Early adoption is permitted, including adoption in any interim period, for periods for which financial statements have not yet been issued. The Company adopted the new standard in December 2018. As a result, the Company will account for collaboration agreements with counterparties that are considered to be a customer in the arrangement within the scope of Topic 606. In March 2019, the FASB issued ASU No. 2019-01 – Leases (Topic 842): Codification Improvements. The standard clarifies the codification more generally and/or corrects unintended application of the guidance. The amendments in this standard include the following items: (Issue 1) Determining the fair value of the underlying asset by lessors that are not manufacturers or dealers, (Issue 2) Presentation on the statement of cash flows—sales-type and direct financing leases and (Issue 3) Transition disclosures related to Topic 250, Accounting Changes and Error Corrections. The amendments in this standard clarify the FASB’s original intent by explicitly providing an exception to the paragraph 250-10-50-3 interim disclosure requirements in the Topic 842 transition disclosure requirements. The new standard is effective on the adoption date of ASU 2016-02. The Company adopted the standard on January 1, 2019 and concluded that adoption of the standard did not have a material impact on its condensed consolidated financial statements.

Basis of Presentation, Use of Estimates and Recent Accounting Pronouncements

3 Months Ended

Mar. 31, 2019

Basis of Presentation, Use of Estimates and Recent Accounting Pronouncements

2. Basis of Presentation, Use of Estimates and Recent Accounting Pronouncements

Basis of Presentation

The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles, or U.S. GAAP, and follow the requirements of the Securities and Exchange Commission, or the SEC, for interim reporting. As permitted under those rules, certain footnotes or other financial information that are normally required by U.S. GAAP have been condensed or omitted, and accordingly the balance sheet as of December 31, 2018 has been derived from audited consolidated financial statements at that date but does not include all of the information required by U.S. GAAP for complete financial statements. These financial statements have been prepared on the same basis as the Company’s annual financial statements and, in the opinion of management, reflect all adjustments (consisting only of normal recurring adjustments) that are necessary for a fair presentation of the Company’s financial information. The results of operations for the three months ended March 31, 2019 are not necessarily indicative of the results to be expected for the year ending December 31, 2019 or for any other interim period or for any other future year.

The accompanying condensed consolidated financial statements and related financial information should be read in conjunction with the audited consolidated financial statements and the related notes thereto for the year ended December 31, 2018 included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2018 filed with the SEC on February 27, 2019.

The condensed consolidated financial statements include the accounts of Aduro Biotech, Inc. and its wholly-owned subsidiaries. All intercompany transactions and balances have been eliminated.

Use of Estimates

The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities and reported amounts of revenue and expenses in the financial statements and accompanying notes. On an ongoing basis, management evaluates its estimates, including those related to revenue recognition, clinical trial accruals, contingent consideration, income taxes, right-of-use asset, lease obligation, and stock-based compensation. Management bases its estimates on historical experience and on various other market-specific and relevant assumptions that management believes to be reasonable under the circumstances. Actual results could differ from these estimates.

Leases

On January 1, 2019, the Company adopted the new standard on leases, Accounting Standard Codification 842, which establishes a comprehensive new lease accounting model. The following steps were taken to be consistent with the guidance in accounting for leases under the new standard. The Company determines if an arrangement is a lease at inception. The Company elected the practical expedient to adopt the policy to not separate lease and non-lease components. Operating leases are included in operating lease right-of-use assets, ROU, and operating lease liabilities on the Company’s consolidated balance sheets. Operating lease ROU assets represent the Company’s right to use an underlying asset for the lease term and operating lease liabilities represent the Company’s obligation to make lease payments arising from the lease. Operating lease ROU assets and operating lease liabilities are recognized based on the present value of lease payments over the lease term. As most of the Company’s leases do not provide an implicit rate, the Company uses its incremental borrowing rate in determining the present value of lease payments. The operating lease ROU asset also includes any lease payments made and excludes lease incentives. The Company’s lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise such options to extend or terminate the lease. Lease expense for lease payments is recognized on a straight-line basis over the lease term.

Stock-Based Compensation

On January 1, 2019, the Company adopted Accounting Standard Update 2018-07, simplifying its accounting for share-based payments to non-employees by aligning it with the accounting for share-based payments to employees, with certain exceptions. The Company measured its stock-based awards made to non-employees based on the estimated fair values of the awards as of the adoption date of January 1, 2019 using the Black-Scholes option-pricing model. Stock-based compensation expense is recognized over the remaining requisite service period using the straight-line method and is based on the value of the portion of stock-based payment awards that is ultimately expected to vest. As such, the Company’s stock-based compensation is reduced for the estimated forfeitures and revised, if necessary, in subsequent periods if actual forfeitures differ from the original estimates.

Recent Accounting Pronouncements

In June 2016, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update, or ASU, No. 2016-13, Financial Instruments—Credit Losses (Topic 326). The standard changes how entities will measure credit losses for most financial assets and certain other instruments that are not measured at fair value through net income. Financial assets measured at amortized cost will be presented at the net amount expected to be collected by using an allowance for credit losses. The standard is effective for fiscal years and interim periods beginning after December 15, 2019. Early adoption is permitted for all periods beginning after December 15, 2018. The Company has evaluated the impact of this guidance and has concluded that adoption of the standard will not have a material impact on its condensed consolidated financial statements.

In August 2018, the FASB issued ASU No. 2018-13 – Fair Value Measurement (Topic 820): Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement. The standard eliminates certain disclosure requirements for fair value measurements for all entities, requires public entities to disclose certain new information, and modifies some disclosure requirements. The new standard is effective for fiscal years and interim periods beginning after December 15, 2019. Early adoption is permitted upon issuance of this ASU. Entities making this election to early adopt are permitted to early adopt the eliminated or modified disclosure requirements and delay the adoption of the new disclosure requirements until their effective date. The Company is currently evaluating the impact that the standard will have on its condensed consolidated financial statements.

Recently Adopted Accounting Pronouncements

In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) (ASC 842), which establishes a comprehensive new lease accounting model. The new standard: (a) clarifies the definition of a lease; (b) requires a dual approach to lease classification similar to current lease classifications; and (c) causes lessees to recognize leases on the balance sheet as a lease liability with a corresponding ROU asset for leases with a lease-term of more than twelve months. The new standard is effective for fiscal years and interim periods beginning after December 15, 2018, with early adoption permitted. A modified retrospective transition approach is required for leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements. In July 2018, the FASB issued ASU No. 2018-11, Leases (Topic 842): Targeted Improvements, an update which provides another transition method, the prospective transition method, which allows entities to initially apply the new lease standard at the adoption date and recognize a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption. The Company adopted the new standard on January 1, 2019 using the prospective transition method.

The Company identified all leases and reviewed the leases to determine the impact of ASC 842 on its condensed consolidated financial statements. The Company has elected to apply all of the practical expedients as a package, which include not reassessing (1) whether any expired or existing contracts are or contain leases, (2) lease classification for any expired or existing leases, and (3) initial direct costs for any existing leases. The Company also elected the practical expedient to not separate lease and non-lease components for its real estate leases. Based on the Company’s assessment, the Company concluded that the adoption of the new standard resulted in the recording of a $22.1 million ROU asset and a $33.8 million lease liability and a derecognition of $11.7 million of deferred rent on the consolidated balance sheet on January 1, 2019. The Company’s adoption of ASU 2016-02, as amended, did not have a material impact on its condensed consolidated statements of operations or condensed consolidated statements of cash flows.

In February 2018, the FASB issued ASU No. 2018-02, Income Statement-Reporting Comprehensive Income (Topic 220). The standard update allows for a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the Tax Cuts and Jobs Act of 2017, or the Tax Act. Consequently, the ASU 2018-02 eliminates the stranded tax effects resulting from the Tax Act. The new standard is effective for fiscal years and interim periods beginning after December 15, 2018. Early adoption is permitted, including adoption in any interim period for reporting periods for which financial statements have not yet been issued. The new standard should be applied either in the period of adoption or retrospectively to each period (or periods) in which the effect of the change in the U.S. federal corporate income tax rate in the Tax Act is recognized. The Company adopted the new standard on January 1, 2019 and due to the full valuation allowance, the Company concluded that there is no impact on its condensed consolidated financial statements.

In June 2018, the FASB issued ASU No. 2018-07 – Compensation-Stock Compensation (Topic 718): Improvements to Non-employee Shared-Based Payment Accounting. The standard update expands the scope of Topic 718 to include share-based payment transactions for acquiring goods and services from non-employees. The new standard simplifies several aspects of Topic 718 by expanding the scope of the following areas to account for non-employee shared-based payment transactions: (1) overall measurement objective, (2) measurement date, (3) awards with performance conditions, and (4) classification reassessment of certain equity-classified awards. The new standard is effective for fiscal years and interim periods beginning after December 15, 2018. Early adoption is permitted, but no earlier than an entity’s adoption date of Topic 606. The Company adopted the new standard on January 1, 2019. As a result, existing non-employee awards were measured as of the adoption date and the related expense will be recognized over the remaining requisite service period using the straight-line method. New awards made to non-employees will be measured at the grant date.

In November 2018, the FASB issued ASU No. 2018-18 – Collaborative Arrangements (Topic 808): Clarifying the Interaction between Topic 808 and Topic 606. The standard update requires transactions in collaborative arrangements to be accounted for under Topic 606, if the counterparty is a customer for a good or service that is a distinct unit of account. The standard update also precludes entities from presenting consideration from transactions with a collaborator that is not a customer together with revenue recognized from contracts with customers. The new standard is effective for fiscal years and interim periods beginning after December 15, 2019. Early adoption is permitted, including adoption in any interim period, for periods for which financial statements have not yet been issued. The Company adopted the new standard in December 2018. As a result, the Company will account for collaboration agreements with counterparties that are considered to be a customer in the arrangement within the scope of Topic 606.

In March 2019, the FASB issued ASU No. 2019-01 – Leases (Topic 842): Codification Improvements. The standard clarifies the codification more generally and/or corrects unintended application of the guidance. The amendments in this standard include the following items: (Issue 1) Determining the fair value of the underlying asset by lessors that are not manufacturers or dealers, (Issue 2) Presentation on the statement of cash flows—sales-type and direct financing leases and (Issue 3) Transition disclosures related to Topic 250, Accounting Changes and Error Corrections. The amendments in this standard clarify the FASB’s original intent by explicitly providing an exception to the paragraph 250-10-50-3 interim disclosure requirements in the Topic 842 transition disclosure requirements. The new standard is effective on the adoption date of ASU 2016-02. The Company adopted the standard on January 1, 2019 and concluded that adoption of the standard did not have a material impact on its condensed consolidated financial statements.