Summary of Significant Accounting Policies	3 Months Ended
Mar. 31, 2022
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Basis of Presentation The accompanying condensed consolidated financial statements of the Company for the three months ended March 31, 2022 and 2021 are unaudited and have been prepared on a basis substantially consistent with the audited financial statements for the year ended December 31, 2021. The year-end condensed consolidated balance sheet data, which is presented for comparative purposes, was derived from audited financial statements, but does not include all disclosures required by accounting principles generally accepted in the U.S. (commonly referred to as “GAAP”). In the opinion of management, the condensed consolidated financial statements include all adjustments, which are of a normal recurring nature, that are necessary to state fairly the results of operations for the reported periods. These financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto of the Company, which are contained in the Company’s Annual Report. The results of the Company’s operations for any interim period are not necessarily indicative of the results of the Company’s operations for any other interim period or for any full fiscal year. Principles of Consolidation The condensed consolidated financial statements include the accounts of Alkermes plc and its wholly-owned subsidiaries as disclosed in Note 2, Summary of Significant Accounting Policies, in the “Notes to Consolidated Financial Statements” accompanying the Company’s Annual Report. Intercompany accounts and transactions have been eliminated. Reclassification The Company reclassified certain prior year amounts on the condensed consolidated balance sheet to conform to the current year presentation. These reclassifications had no impact on the previously reported total assets, liabilities or shareholders’ equity. Use of Estimates The preparation of the Company’s condensed consolidated financial statements in accordance with GAAP requires that Company management make estimates, judgments and assumptions that may affect the reported amounts of assets, liabilities, revenues and expenses, and related disclosure of contingent assets and liabilities. On an ongoing basis, the Company evaluates its estimates, judgments and methodologies, including, but not limited to, those related to revenue from contracts with its customers and related allowances, impairment and amortization of intangibles and long-lived assets, share-based compensation, income taxes including the valuation allowance for deferred tax assets, valuation of investments, contingent consideration and litigation. The Company bases its estimates on historical experience and on various other assumptions that are believed to be reasonable, the results of which form the basis for making judgments about the carrying values of assets and liabilities. Actual results may differ from these estimates under different conditions or using different assumptions. Segment Information The Company operates as one business segment, which is the business of developing, manufacturing and commercializing medicines designed to address unmet medical needs of patients in major therapeutic areas. The Company’s chief decision maker, the Chief Executive Officer and chairman of the Company’s board of directors, reviews the Company’s operating results on an aggregate basis and manages the Company’s operations as a single operating unit. Risks and Uncertainties In March 2020, COVID-19 was declared a global pandemic by the World Health Organization. To date, COVID-19 has surfaced in nearly all regions around the world and resulted in travel restrictions and business slowdowns and/or shutdowns in affected areas. Ireland, all U.S. states, and many local jurisdictions and countries around the world have, at times during the pandemic, issued and implemented quarantines, vaccine and masking mandates, restrictive executive orders and other similar government orders, restrictions, and recommendations for their residents to help control the spread of COVID-19, and may continue to do so while the pandemic persists. Such orders, mandates, restrictions and/or recommendations, and/or the perception that additional orders, mandates, restrictions or recommendations could occur, have, at times during the pandemic, resulted in widespread interruptions and closures of businesses, including healthcare systems that serve people living with addiction and serious mental illness, work stoppages, slowdowns and/or delays, remote work policies and travel restrictions, among other effects. The COVID-19 pandemic has caused, and the Company expects may continue to cause, varying degrees of disruption to its employees and its business operations. While the Company has continued to operate its manufacturing facilities and supply its medicines without interruption throughout the pandemic, it has at times during the pandemic experienced labor or supply chain disruptions at its manufacturing facilities, and may continue to experience such disruptions while the pandemic persists. In addition, while the Company has continued to conduct R&D activities, including its ongoing clinical trials, the COVID-19 pandemic has at times impacted the timelines of certain of its early-stage discovery efforts and clinical trials, and may continue to impact such timelines while the pandemic persists. The Company works with its internal teams, its clinical investigators, R&D vendors and critical supply chain vendors to continually assess, and mitigate, the potential impact of COVID-19 on its manufacturing operations and R&D activities. A number of the marketed products from which the Company derives revenue, including manufacturing and royalty revenue, are injectable medications administered by healthcare professionals. Given developments that have transpired to date, and may continue to transpire, in response to the pandemic, including business closures, travel restrictions, quarantine, testing and/or vaccine mandates and other protocols, labor shortages, and other restrictive measures, commercial sales of these marketed products have been adversely impacted to varying degrees during the pandemic and may continue to be adversely impacted while the pandemic persists. In addition, the Company relies upon third parties for many aspects of its business, including the provision of goods and services related to the manufacture of its clinical products and its and its partners’ marketed products, the conduct of its clinical trials, and the sale of its proprietary marketed products and the marketed products of its licensees from which the Company receives manufacturing and royalty revenue. Any prolonged material disruption to the third parties on which the Company relies could negatively impact the Company’s ability to conduct business in the manner and on the timelines presently planned, which could have a material adverse impact on the Company’s business, results of operations and financial condition. Due to numerous uncertainties surrounding the ongoing COVID-19 pandemic, the actual impact of the pandemic on the Company’s financial condition and operating results may differ from its current projections. These uncertainties include, among other things, the ultimate severity and duration of the pandemic and the manner in which it continues to evolve, including the emergence, prevalence and severity of new or existing COVID-19 variants, and future developments in response thereto, which are highly uncertain and cannot be predicted as of the date of this Form 10-Q. New Accounting Pronouncements From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board (the “FASB”) or other standard-setting bodies that are adopted by the Company as of the specified effective date. Unless otherwise discussed, the Company believes that the impact of recently issued standards that are not yet effective will not have a material impact on its financial position or results of operations upon adoption.

Summary of Significant Accounting Policies

3 Months Ended

Mar. 31, 2022

Summary of Significant Accounting Policies

2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Basis of Presentation

The accompanying condensed consolidated financial statements of the Company for the three months ended March 31, 2022 and 2021 are unaudited and have been prepared on a basis substantially consistent with the audited financial statements for the year ended December 31, 2021. The year-end condensed consolidated balance sheet data, which is presented for comparative purposes, was derived from audited financial statements, but does not include all disclosures required by accounting principles generally accepted in the U.S. (commonly referred to as “GAAP”). In the opinion of management, the condensed consolidated financial statements include all adjustments, which are of a normal recurring nature, that are necessary to state fairly the results of operations for the reported periods.

These financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto of the Company, which are contained in the Company’s Annual Report. The results of the Company’s operations for any interim period are not necessarily indicative of the results of the Company’s operations for any other interim period or for any full fiscal year.

Principles of Consolidation

The condensed consolidated financial statements include the accounts of Alkermes plc and its wholly-owned subsidiaries as disclosed in Note 2, Summary of Significant Accounting Policies, in the “Notes to Consolidated Financial Statements” accompanying the Company’s Annual Report. Intercompany accounts and transactions have been eliminated.

Reclassification

The Company reclassified certain prior year amounts on the condensed consolidated balance sheet to conform to the current year presentation. These reclassifications had no impact on the previously reported total assets, liabilities or shareholders’ equity.

Use of Estimates

The preparation of the Company’s condensed consolidated financial statements in accordance with GAAP requires that Company management make estimates, judgments and assumptions that may affect the reported amounts of assets, liabilities, revenues and expenses, and related disclosure of contingent assets and liabilities. On an ongoing basis, the Company evaluates its estimates, judgments and methodologies, including, but not limited to, those related to revenue from contracts with its customers and related allowances, impairment and amortization of intangibles and long-lived assets, share-based compensation, income taxes including the valuation allowance for deferred tax assets, valuation of investments, contingent consideration and litigation. The Company bases its estimates on historical experience and on various other assumptions that are believed to be reasonable, the results of which form the basis for making judgments about the carrying values of assets and liabilities. Actual results may differ from these estimates under different conditions or using different assumptions.

Segment Information

The Company operates as one business segment, which is the business of developing, manufacturing and commercializing medicines designed to address unmet medical needs of patients in major therapeutic areas. The Company’s chief decision maker, the Chief Executive Officer and chairman of the Company’s board of directors, reviews the Company’s operating results on an aggregate basis and manages the Company’s operations as a single operating unit.

Risks and Uncertainties

In March 2020, COVID-19 was declared a global pandemic by the World Health Organization. To date, COVID-19 has surfaced in nearly all regions around the world and resulted in travel restrictions and business slowdowns and/or shutdowns in affected areas. Ireland, all U.S. states, and many local jurisdictions and countries around the world have, at times during the pandemic, issued and implemented quarantines, vaccine and masking mandates, restrictive executive orders and other similar government orders, restrictions, and recommendations for their residents to help control the spread of COVID-19, and may continue to do so while the pandemic persists. Such orders, mandates, restrictions and/or recommendations, and/or the perception that additional orders, mandates, restrictions or recommendations could occur, have, at times during the pandemic, resulted in widespread interruptions and closures of businesses, including healthcare systems that serve people living with addiction and serious mental illness, work stoppages, slowdowns and/or delays, remote work policies and travel restrictions, among other effects.

The COVID-19 pandemic has caused, and the Company expects may continue to cause, varying degrees of disruption to its employees and its business operations. While the Company has continued to operate its manufacturing facilities and supply its medicines without interruption throughout the pandemic, it has at times during the pandemic experienced labor or supply chain disruptions at its manufacturing facilities, and may continue to experience such disruptions while the pandemic persists. In addition, while the Company has continued to conduct R&D activities, including its ongoing clinical trials, the COVID-19 pandemic has at times impacted the timelines of certain of its early-stage discovery efforts and clinical trials, and may continue to impact such timelines while the pandemic persists. The Company works with its internal teams, its clinical investigators, R&D vendors and critical supply chain vendors to continually assess, and mitigate, the potential impact of COVID-19 on its manufacturing operations and R&D activities.

A number of the marketed products from which the Company derives revenue, including manufacturing and royalty revenue, are injectable medications administered by healthcare professionals. Given developments that have transpired to date, and may continue to transpire, in response to the pandemic, including business closures, travel restrictions, quarantine, testing and/or vaccine mandates and other protocols, labor shortages, and other restrictive measures, commercial sales of these marketed products have been adversely impacted to varying degrees during the pandemic and may continue to be adversely impacted while the pandemic persists.

In addition, the Company relies upon third parties for many aspects of its business, including the provision of goods and services related to the manufacture of its clinical products and its and its partners’ marketed products, the conduct of its clinical trials, and the sale of its proprietary marketed products and the marketed products of its licensees from which the Company receives manufacturing and royalty revenue. Any prolonged material disruption to the third parties on which the Company relies could negatively impact the Company’s ability to conduct business in the manner and on the timelines presently planned, which could have a material adverse impact on the Company’s business, results of operations and financial condition.

Due to numerous uncertainties surrounding the ongoing COVID-19 pandemic, the actual impact of the pandemic on the Company’s financial condition and operating results may differ from its current projections. These uncertainties include, among other things, the ultimate severity and duration of the pandemic and the manner in which it continues to evolve, including the emergence, prevalence and severity of new or existing COVID-19 variants, and future developments in response thereto, which are highly uncertain and cannot be predicted as of the date of this Form 10-Q.

New Accounting Pronouncements

From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board (the “FASB”) or other standard-setting bodies that are adopted by the Company as of the specified effective date. Unless otherwise discussed, the Company believes that the impact of recently issued standards that are not yet effective will not have a material impact on its financial position or results of operations upon adoption.