Summary of Significant Accounting Policies	12 Months Ended
Dec. 31, 2021
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Cash and Cash Equivalents The Company classifies as cash and cash equivalents amounts on deposit in banks and cash invested temporarily in various instruments, primarily money market accounts, with original maturities of three months or less at time of purchase. The carrying amounts reported in the consolidated balance sheets represent the fair values of cash and cash equivalents. Restricted Cash Restricted cash represents a letter of credit collateralized by a certificate of deposit in the same amount as required under the terms of the Company's laboratory and office space lease entered into in May 2021. Concentration of Credit Risk The Company maintains its cash in financial institution accounts that may at times exceed federally insured limits. The cash balances in the financial institutions are insured by the Federal Deposit Insurance Corporation ("FDIC") up to $250,000. Cash may also be maintained at commercial institutions that are not insured by the FDIC. For the years ended December 31, 2021 and 2020, 100% of the Company’s revenue was attributable to three collaborators representing 68%, 17% and 15% in 2021, and 37%, 32% and 31% in 2020. For each of the years ended December 31, 2021 and 2020, one collaborator accounted for the entire accounts receivable balance. For the year ended December 31, 2019, 57% of the Company’s revenue was attributable to a license contributed to Oerth, and two collaborators represented 19% and 16% of total revenue. Marketable Securities The Company's marketable securities are classified as available-for-sale securities and are carried at their fair value based on the quoted market prices of the securities, with unrealized gains and losses reported as accumulated other comprehensive income (loss), a separate component of stockholders' equity. Realized gains and losses on available-for-sale securities are included in other income in the period earned or incurred. Property, Equipment, and Leasehold Improvements Property and equipment are recorded at cost. Depreciation is calculated using the straight-line method over the estimated useful lives, which range from three years for office equipment to five years for laboratory equipment. Maintenance and repairs which do not extend the lives of the assets are charged directly to expense as incurred. Upon retirement or disposal, cost and related accumulated depreciation are removed from the related accounts, and any resulting gain or loss is recognized as a component of income or loss for the period. Leasehold improvements are recorded at cost and amortized using the straight-line method over the shorter of the lease term or the useful life of the asset. Impairment of Long-Lived Assets The Company evaluates the carrying value of long-lived assets when indications of potential impairments are present. The Company adjusts the carrying value of the long-lived assets if the sum of undiscounted expected future cash flows is less than the carrying value. No such impairments were recorded during 2021, 2020 or 2019. Segment Information Operating segments are defined as components of an enterprise about which separate discrete information is available for evaluation by the chief operating decision maker in assessing performance and allocating resources. The Company, through its Chief Executive Officer in his role as chief operating decision maker, views Company operations and manages the business as one operating segment. All of the Company’s tangible assets are held in the United States and all of the Company’s revenue has been generated in the United States. Revenue Recognition and Deferred Revenue Revenues from Contracts The Company recognizes revenue under Accounting Standards Codification ("ASC") 606, Revenue from Contracts with Customers. The Company’s revenue is generated through research collaboration and license agreements with pharmaceutical partners. The terms of these agreements contain multiple goods and services which may include (i) licenses, (ii) research and development activities, and (iii) participation in joint research and development steering committees. The terms of these agreements may include non-refundable, upfront license or option fees, payments for research and development activities, payments upon the achievement of certain milestones, and royalty payments based on product sales derived from the collaboration. Under ASC 606, the Company evaluates whether the license agreement, research and development services, and participation in research and development steering committees, represent separate or combined performance obligations. The Company has determined that these services within its existing contracts represent a combined single performance obligation. The research collaboration and license agreements typically include contingent milestone payments related to specified preclinical and clinical development milestones and regulatory milestones. These milestone payments represent variable consideration to be included within the transaction price using the most likely amount method. The Company determined that the most likely amount to be recognized was zero, against which no constraint was applied. The Company will continue to assess the probability of significant reversals for any amounts that become likely to be realized prior to recognizing the variable consideration associated with these payments within the transaction price. Revenue is recognized ratably over the Company’s expected performance period under each respective arrangement. The Company makes its best estimate of the period over which the Company expects to fulfill the Company’s performance obligations, which includes access to technology through the license agreement and research activities. Given the uncertainties of these collaboration arrangements, significant judgment is required to determine the duration of the performance period. For the years ended December 31, 2021, 2020 and 2019, the transaction price allocated to the combined performance obligation identified under the individual research collaboration and license agreements was recognized as revenue on either a straight-line basis over the estimated performance period under the arrangement or over the estimated performance period based on the Company’s best estimate of costs to be incurred. Straight-line basis was considered the best measure of progress for certain agreements in which control of the combined obligation transfers to the customers, due to the contract containing license rights to technology, research and development services, and joint committee participation, which in totality are expected to occur ratably over the performance period. The Company’s contracts may also call for certain sales-based milestone and royalty payments upon successful commercialization of a target. The Company recognizes revenues from sales-based milestone and royalty payments at the later of a) the occurrence of the subsequent sale, or b) the performance obligation to which some or all of the sales-based milestone or royalty payments has been allocated has been satisfied (or partially satisfied). The Company anticipates recognizing these milestones and royalty payments if and when subsequent sales are generated by the customer from the use of the technology. To date, no revenue from these sales-based milestone and royalty payments has been recognized for any periods. Amounts received prior to satisfying the above revenue recognition criteria are recorded as contract liabilities in the Company’s accompanying consolidated balance sheets. The Company expenses direct and incremental costs to obtaining and fulfilling a contract as and when incurred if the expected amortization period of the asset that would be recognized is one year or less, or if the amount of the asset is immaterial. Otherwise, such costs are capitalized as collaboration contract assets and amortized as general and administrative expenses over the total estimated period of performance of each underlying contract. The Company also recognized revenue under ASC 606 from its contribution of a license to Oerth in 2019. See Note 10. Equity Method Investments The Company accounts for investments for which it does not have a controlling interest in accordance with ASC 323, Investments – Equity Method and Joint Ventures. The Company recognizes its pro-rata share of income and losses in the investment in “Loss from equity method investment” on the consolidated statement of operations and comprehensive loss, with a corresponding change to the investment in equity method investment on the consolidated balance sheet until such investment is reduced to zero. Income Taxes Arvinas, Inc. and its wholly owned subsidiaries use the asset and liability method of accounting for income taxes, as set forth in ASC 740, Accounting for Income Taxes. Under this method, deferred tax assets and liabilities are recognized for the expected future tax consequence of temporary differences between the carrying amounts and the tax basis of assets and liabilities and net operating loss carry forwards, all calculated using presently enacted tax rates. A valuation allowance is established to reduce deferred tax assets to their estimated realizable value. The Company provides a valuation allowance to the extent that it is more likely than not that all or a portion of the deferred tax assets will not be realized. Management has evaluated the effect of ASC 740 guidance related to uncertain income tax positions and concluded that the Company has no significant uncertain income tax positions at December 31, 2021 and 2020. Equity-based Compensation The Company measures employee, board of director and consultant equity-based compensation for stock option and restricted stock grants based on the grant date fair value of the equity awards. Equity-based compensation expense is recognized over the requisite service period of the awards, net of estimated forfeitures. Estimated forfeitures are updated on a periodic basis based on actual experience. For equity awards that have a performance condition, the Company recognizes compensation expense based on its assessment of the probability that the performance condition will be achieved. The Company classifies equity-based compensation expense in its consolidated statement of operations in the same manner in which the award recipient’s salary and related costs are classified or in which the award recipient’s service payments are classified. Research and Development Expenses Research and development expenses include (i) employee-related expenses, including salaries, benefits, travel, and stock-based compensation expense; (ii) external research and development expenses incurred under arrangements with third parties, such as contract research organization agreements, investigational sites, and consultants; (iii) the cost of acquiring, developing, and manufacturing clinical study materials; (iv) costs associated with preclinical and clinical activities and regulatory operations; and (v) costs incurred in development of intellectual property. Costs incurred in connection with research and development activities are expensed as incurred. The Company enters into consulting, research, and other agreements with commercial entities, researchers, universities, and others for the provision of goods and services. Such arrangements are generally cancellable upon reasonable notice and payment of costs incurred. Costs are considered incurred based on an evaluation of the progress to completion of specific tasks under each contract using information and data provided by the respective vendors, including the Company’s clinical sites. These costs consist of direct and indirect costs associated with specific projects, as well as fees paid to various entities that perform certain research on behalf of the Company. Depending upon the timing of payments to the service providers, the Company recognizes prepaid expenses or accrued expenses related to these costs. These accrued or prepaid expenses are based on management’s estimates of the work performed under service agreements, milestones achieved, and experience with similar contracts. The Company monitors each of these factors and adjusts estimates accordingly. Fair Value Measurements ASC Topic 820, Fair Value Measurements and Disclosures, requires disclosure of the fair value of financial instruments held by the Company. ASC 825, Financial Instruments, defines fair value and establishes a three-level valuation hierarchy for disclosures of fair value measurement that enhances disclosure requirements for fair value measures. The three levels of valuation hierarchy are defined as follows: Level 1— Inputs are based upon observable or quoted prices (unadjusted) for identical instruments traded in active markets. Level 2— Inputs are based upon quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, and model-based valuation techniques for which all significant assumptions are observable in the market or can be corroborated by observable market data for substantially the full term of the assets or liabilities. The Company’s Level 2 investments consist primarily of corporate notes and bonds and U.S. government and agency securities. Level 3— Inputs are generally unobservable and typically reflect management’s estimates of assumptions that market participants would use in pricing the asset or liability. The fair values are therefore determined using model-based techniques that include option pricing models, discounted cash flow models, and similar techniques. In determining fair value, the Company utilizes valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs to the extent possible as well as considers counterparty credit risk in its assessment of fair value. The Company’s marketable securities consist of corporate bonds and government securities which are adjusted to fair value at each balance sheet date, based on quoted prices, which are considered Level 2 inputs. During the year ended December 31, 2021, a non-recurring fair value measurement was applied to determine the fair value of the 3,457,815 shares of the Company’s common stock (the "Shares") issued and sold to Pfizer, Inc. ("Pfizer") under the Stock Purchase Agreement entered into between the Company and Pfizer in July 2021 (the “Pfizer Stock Purchase Agreement”) at a price of $101.22 per share, for an aggregate purchase price of up to $350.0 million (the “Pfizer Equity Transaction”), which was consummated in September 2021. The fair value was determined by applying the discount due to lack of marketability during the contractual lock-up period to the public trading price of the common stock, which is a Level 1 input, on the date of sale. The Company accounted for the lack of marketability during the contractual lock-up period, by utilizing put option models, which are considered Level 3 inputs. See Note 4. Net Loss per Common Share Basic net loss per common share is computed by dividing net loss by the weighted-average number of common shares outstanding during the period. Diluted net loss per share is computed using the weighted-average number of common shares outstanding during the period and, if dilutive, the weighted average number of potential shares of common shares. New Accounting Pronouncements Recently Adopted Accounting Pronouncements Effective January 1, 2021, the Company adopted ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes, (“ASU 2019-12”) which simplifies the accounting for income taxes by removing certain exceptions to the general principles in ASC 740 and clarifies and amends existing guidance to improve consistent application. ASU 2019-12 requires, among other requirements, the Company to recognize as an income tax the effect of state hybrid taxes that are based on the greater of an income-based tax and a capital-based tax. Adoption of ASU 2019-12 did not have a material impact on the Company’s financial statements since the Company has no state income tax liabilities due to its net operating losses. Additionally, the Company has not recorded any income tax benefits from these losses due to uncertainty of realizing the related tax benefit.

The Company classifies as cash and cash equivalents amounts on deposit in banks and cash invested temporarily in various instruments, primarily money market accounts, with original maturities of three months or less at time of purchase. The carrying amounts reported in the consolidated balance sheets represent the fair values of cash and cash equivalents.

The Company maintains its cash in financial institution accounts that may at times exceed federally insured limits. The cash balances in the financial institutions are insured by the Federal Deposit Insurance Corporation ("FDIC") up to $250,000. Cash may also be maintained at commercial institutions that are not insured by the FDIC.

For the years ended December 31, 2021 and 2020, 100% of the Company’s revenue was attributable to three collaborators representing 68%, 17% and 15% in 2021, and 37%, 32% and 31% in 2020. For each of the years ended December 31, 2021 and 2020, one collaborator accounted for the entire accounts receivable balance. For the year ended December 31, 2019, 57% of the Company’s revenue was attributable to a license contributed to Oerth, and two collaborators represented 19% and 16% of total revenue.

The Company's marketable securities are classified as available-for-sale securities and are carried at their fair value based on the quoted market prices of the securities, with unrealized gains and losses reported as accumulated other comprehensive income (loss), a separate component of stockholders' equity. Realized gains and losses on available-for-sale securities are included in other income in the period earned or incurred.

Property and equipment are recorded at cost. Depreciation is calculated using the straight-line method over the estimated useful lives, which range from three years for office equipment to five years for laboratory equipment. Maintenance and repairs which do not extend the lives of the assets are charged directly to expense as incurred. Upon retirement or disposal, cost and related accumulated depreciation are removed from the related accounts, and any resulting gain or loss is recognized as a component of income or loss for the period. Leasehold improvements are recorded at cost and amortized using the straight-line method over the shorter of the lease term or the useful life of the asset.

The Company evaluates the carrying value of long-lived assets when indications of potential impairments are present. The Company adjusts the carrying value of the long-lived assets if the sum of undiscounted expected future cash flows is less than the carrying value. No such impairments were recorded during 2021, 2020 or 2019.

Operating segments are defined as components of an enterprise about which separate discrete information is available for evaluation by the chief operating decision maker in assessing performance and allocating resources. The Company, through its Chief Executive Officer in his role as chief operating decision maker, views Company operations and manages the business as one operating segment. All of the Company’s tangible assets are held in the United States and all of the Company’s revenue has been generated in the United States.

The Company recognizes revenue under Accounting Standards Codification ("ASC") 606, Revenue from Contracts with Customers. The Company’s revenue is generated through research collaboration and license agreements with pharmaceutical partners. The terms of these agreements contain multiple goods and services which may include (i) licenses, (ii) research and development activities, and (iii) participation in joint

research and development steering committees. The terms of these agreements may include non-refundable, upfront license or option fees, payments for research and development activities, payments upon the achievement of certain milestones, and royalty payments based on product sales derived from the collaboration. Under ASC 606, the Company evaluates whether the license agreement, research and development services, and participation in research and development steering committees, represent separate or combined performance obligations. The Company has determined that these services within its existing contracts represent a combined single performance obligation.

The research collaboration and license agreements typically include contingent milestone payments related to specified preclinical and clinical development milestones and regulatory milestones. These milestone payments represent variable consideration to be included within the transaction price using the most likely amount method. The Company determined that the most likely amount to be recognized was zero, against which no constraint was applied. The Company will continue to assess the probability of significant reversals for any amounts that become likely to be realized prior to recognizing the variable consideration associated with these payments within the transaction price.

Revenue is recognized ratably over the Company’s expected performance period under each respective arrangement. The Company makes its best estimate of the period over which the Company expects to fulfill the Company’s performance obligations, which includes access to technology through the license agreement and research activities. Given the uncertainties of these collaboration arrangements, significant judgment is required to determine the duration of the performance period.

For the years ended December 31, 2021, 2020 and 2019, the transaction price allocated to the combined performance obligation identified under the individual research collaboration and license agreements was recognized as revenue on either a straight-line basis over the estimated performance period under the arrangement or over the estimated performance period based on the Company’s best estimate of costs to be incurred. Straight-line basis was considered the best measure of progress for certain agreements in which control of the combined obligation transfers to the customers, due to the contract containing license rights to technology, research and development services, and joint committee participation, which in totality are expected to occur ratably over the performance period.

The Company’s contracts may also call for certain sales-based milestone and royalty payments upon successful commercialization of a target. The Company recognizes revenues from sales-based milestone and royalty payments at the later of a) the occurrence of the subsequent sale, or b) the performance obligation to which some or all of the sales-based milestone or royalty payments has been allocated has been satisfied (or partially satisfied). The Company anticipates recognizing these milestones and royalty payments if and when subsequent sales are generated by the customer from the use of the technology. To date, no revenue from these sales-based milestone and royalty payments has been recognized for any periods.

The Company expenses direct and incremental costs to obtaining and fulfilling a contract as and when incurred if the expected amortization period of the asset that would be recognized is one year or less, or if the amount of the asset is immaterial. Otherwise, such costs are capitalized as collaboration contract assets and amortized as general and administrative expenses over the total estimated period of performance of each underlying contract.

The Company accounts for investments for which it does not have a controlling interest in accordance with ASC 323, Investments – Equity Method and Joint Ventures. The Company recognizes its pro-rata share of income and losses in the investment in “Loss from equity method investment” on the consolidated statement of operations and comprehensive loss, with a corresponding change to the investment in equity method investment on the consolidated balance sheet until such investment is reduced to zero.

Arvinas, Inc. and its wholly owned subsidiaries use the asset and liability method of accounting for income taxes, as set forth in ASC 740, Accounting for Income Taxes. Under this method, deferred tax assets and liabilities are recognized for the expected future tax consequence of temporary differences between the carrying amounts and the tax basis of assets and liabilities and net operating loss carry forwards, all calculated using presently enacted tax rates. A valuation allowance is established to reduce deferred tax assets to their estimated realizable value. The Company provides a valuation allowance to the extent that it is more likely than not that all or a portion of the deferred tax assets will not be realized.

The Company measures employee, board of director and consultant equity-based compensation for stock option and restricted stock grants based on the grant date fair value of the equity awards. Equity-based compensation expense is recognized over the requisite service period of the awards, net of estimated forfeitures. Estimated forfeitures are updated on a periodic basis based on actual experience. For equity awards that have a performance condition, the Company recognizes compensation expense based on its assessment of the probability that the performance condition will be achieved.

The Company classifies equity-based compensation expense in its consolidated statement of operations in the same manner in which the award recipient’s salary and related costs are classified or in which the award recipient’s service payments are classified.

Research and development expenses include (i) employee-related expenses, including salaries, benefits, travel, and stock-based compensation expense; (ii) external research and development expenses incurred under arrangements with third parties, such as contract research organization agreements, investigational sites, and consultants; (iii) the cost of acquiring, developing, and manufacturing clinical study materials; (iv) costs associated with preclinical and clinical activities and regulatory operations; and (v) costs incurred in development of intellectual property. Costs incurred in connection with research and development activities are expensed as incurred.

The Company enters into consulting, research, and other agreements with commercial entities, researchers, universities, and others for the provision of goods and services. Such arrangements are generally cancellable upon reasonable notice and payment of costs incurred. Costs are considered incurred based on an evaluation of the progress to completion of specific tasks under each contract using information and data provided by the respective vendors, including the Company’s clinical sites. These costs consist of direct and indirect costs associated with specific projects, as well as fees paid to various entities that perform certain research on behalf of the Company. Depending upon the timing of payments to the service providers, the Company recognizes prepaid expenses or accrued expenses related to these costs. These accrued or prepaid expenses are based on management’s estimates of the work performed under service agreements, milestones achieved, and experience with similar contracts. The Company monitors each of these factors and adjusts estimates accordingly.

ASC Topic 820, Fair Value Measurements and Disclosures, requires disclosure of the fair value of financial instruments held by the Company. ASC 825, Financial Instruments, defines fair value and establishes a three-level valuation hierarchy for disclosures of fair value measurement that enhances disclosure requirements for fair value measures. The three levels of valuation hierarchy are defined as follows:

Level 2— Inputs are based upon quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, and model-based valuation techniques for which all significant assumptions are observable in the market or can be corroborated by observable market data for substantially the full term of the assets or liabilities. The Company’s Level 2 investments consist primarily of corporate notes and bonds and U.S. government and agency securities.

Level 3— Inputs are generally unobservable and typically reflect management’s estimates of assumptions that market participants would use in pricing the asset or liability. The fair values are therefore determined using model-based techniques that include option pricing models, discounted cash flow models, and similar techniques.

In determining fair value, the Company utilizes valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs to the extent possible as well as considers counterparty credit risk in its assessment of fair value.

The Company’s marketable securities consist of corporate bonds and government securities which are adjusted to fair value at each balance sheet date, based on quoted prices, which are considered Level 2 inputs. During the year ended December 31, 2021, a non-recurring fair value measurement was applied to determine the fair value of the 3,457,815 shares of the Company’s common stock (the "Shares") issued and sold to Pfizer, Inc. ("Pfizer") under the Stock Purchase Agreement entered into between the Company and Pfizer in July 2021 (the “Pfizer Stock Purchase Agreement”) at a price of $101.22 per share, for an aggregate purchase price of up to $350.0 million (the “Pfizer Equity Transaction”), which was consummated in September 2021. The fair value was determined by applying the discount due to lack of marketability during the contractual lock-up period to the public trading price of the common stock, which is a Level 1 input, on the date of sale. The Company accounted for the lack of marketability during the contractual lock-up period, by utilizing put option models, which are considered Level 3 inputs. See Note 4.

Basic net loss per common share is computed by dividing net loss by the weighted-average number of common shares outstanding during the period. Diluted net loss per share is computed using the weighted-average number of common shares outstanding during the period and, if dilutive, the weighted average number of potential shares of common shares.

Effective January 1, 2021, the Company adopted ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes, (“ASU 2019-12”) which simplifies the accounting for income taxes by removing certain exceptions to the general principles in ASC 740 and clarifies and amends existing guidance to improve consistent application. ASU 2019-12 requires, among other requirements, the Company to recognize as an income tax the effect of state hybrid taxes that are based on the greater of an income-based tax and a capital-based tax. Adoption of ASU 2019-12 did not have a material impact on the Company’s financial statements since the Company has no state income tax liabilities due to its net operating losses. Additionally, the Company has not recorded any income tax benefits from these losses due to uncertainty of realizing the related tax benefit.