Summary of Significant Accounting Policies	9 Months Ended
Summary of Significant Accounting Policies	Sep. 30, 2023
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Nature of Operations. Avadel Pharmaceuticals plc (Nasdaq: AVDL) (“Avadel,” the “Company,” “we,” “our,” or “us”) is a biopharmaceutical company. The Company is registered as an Irish public limited company. The Company’s headquarters are in Dublin, Ireland with operations in Dublin, Ireland and St. Louis, Missouri, United States (“U.S.”). LUMRYZ, formally known as FT218, is an extended-release formulation of sodium oxybate indicated to be taken once at bedtime for the treatment of cataplexy or excessive daytime sleepiness (“EDS”) in adults with narcolepsy. LUMRYZ was approved by the U.S. Food and Drug Administration (“FDA”) on May 1, 2023. The FDA also granted Orphan Drug Exclusivity (“ODE”) to LUMRYZ for a period of seven years until May 1, 2030. In June 2023, the Company commercially launched LUMRYZ in the U.S. In approving LUMRYZ, the FDA approved a risk evaluation and mitigation strategy (“REMS”) for LUMRYZ to help ensure that the benefits of the drug in the treatment of cataplexy and EDS in narcolepsy outweigh the risks of serious adverse outcomes resulting from inappropriate prescribing, misuse, abuse, and diversion of the drug. Under this REMS, healthcare providers, pharmacies, practitioners, or health care settings that dispense the drug must be specially certified and the drug must be dispensed to patients with documentation of safe use conditions. As of the date of this Quarterly Report, the Company’s only commercialized product is LUMRYZ. The Company continues to evaluate opportunities to expand its product portfolio. Liquidity. The accompanying unaudited condensed consolidated financial statements are prepared in accordance with accounting principles generally accepted in the U.S. (“U.S. GAAP”) applicable to a going concern, which contemplates the realization of assets and the satisfaction of liabilities in the normal course of business. On March 29, 2023, the Company and Avadel CNS Pharmaceuticals, LLC, an indirect wholly-owned subsidiary of the Company (“Avadel CNS”) entered into a royalty purchase agreement (“RPA”) with RTW Investments, L.P. (“RTW”) that could provide the Company up to $75,000 of royalty financing in two tranches. The first tranche of $30,000 became available upon satisfaction of certain conditions which included the Company’s first shipment of LUMRYZ. The second tranche is available to use, at the Company’s election, if it achieves quarterly net revenue of $25,000 by the quarter ending June 30, 2024. The second tranche expires if the Company does not elect to use it by August 31, 2024. On August 1, 2023, the Company received the first tranche of $30,000. At March 31, 2023, the Company had outstanding $117,375 aggregate principal amount of its 4.50% exchangeable senior notes due October 2023 (the “October 2023 Notes”). Over the course of April 3 and April 4, 2023, Avadel Finance Cayman Limited, a Cayman Islands exempted company and an indirect wholly-owned subsidiary of the Company (the “Issuer”), completed an exchange of $96,188 of its $117,375 October 2023 Notes for $106,268 of a new series 6.0% exchangeable notes due April 2027 (the “April 2027 Notes”) (the “2023 Exchange Transaction”). The Issuer settled, with a combination of cash and American Depositary Shares (“ADSs”), the remaining $21,187 aggregate principal amount of the October 2023 Notes in October 2023. The aggregate amount of cash and ADSs delivered to holders for the October 2023 Notes and accrued and unpaid interest was $21,641 and 408 ADSs, respectively. On April 3, 2023, the Company completed the sale of 12,205 ordinary shares, nominal value $0.01 per share (“Ordinary Shares”) in the form of ADSs and 4,706 Series B Non-Voting Convertible Preferred Shares (“Series B Preferred Shares”) in an underwritten public offering. The Company received proceeds, net of underwriter fees and issuance costs of $134,151. On May 31, 2023 and in accordance with the terms of the Indenture of the April 2027 Notes (the “Indenture”), dated as of April 3, 2023, the Issuer exercised its option to exchange (the “Mandatory Exchange”) $106,268 of aggregate principal amount of the April 2027 Notes, which represents all of the April 2027 Notes outstanding under the Indenture. The Mandatory Exchange consideration per one thousand dollars of principal April 2027 Notes exchanged consisted of 116.1846 of the Company’s ADSs, representing a corresponding number of the Company’s ordinary shares, nominal value $0.01 per share, plus accrued and unpaid interest thereon. The aggregate amount of ADSs and cash in respect of accrued and unpaid interest delivered to holders of Notes in the Mandatory Exchange was 12,347 ADSs and $1,470, respectively. The Mandatory Exchange closed on June 26, 2023. At-the-Market Offering Program On February 5, 2020, the Company entered into an Open Market Sale AgreementSM (the “Sales Agreement”) with Jefferies LLC (“Jefferies”) with respect to an at-the-market offering program (“ATM Program”) under which the Company may offer and sell its ADSs (such ADSs sold under the ATM Program, “ATM ADSs”) through Jefferies as its sales agent. The Company agreed to pay Jefferies a commission up to 3.0% of the aggregate gross sales proceeds of such ATM ADSs. The initial aggregate offering price of the ATM Program was up to $50,000 of ADSs pursuant to its prospectus, dated February 14, 2020, included with the Company’s Registration Statement on Form S-3 (File No. 333-236258) (the “2020 Prospectus”). In August 2022, the Company filed an additional prospectus, dated September 12, 2022, included with the Company’s new Registration Statement on Form S-3 (File No. 333-267198) (the “2022 Prospectus”), in order to allocate up to $100,000 in additional ADSs to the ATM Program. The 2020 Shelf Registration expired on February 14, 2023. Pursuant to the Sales Agreement, the Company issued and sold 1,564 ADSs during the nine months ended September 30, 2023, resulting in net proceeds to the Company of approximately $11,913. The Company may offer and sell up to an additional $96,064 of ADSs under the ATM Program that remain available for sale pursuant to the 2022 Prospectus. Basis of Presentation. The unaudited condensed consolidated balance sheet as of September 30, 2023, which is derived from the prior year 2022 audited consolidated financial statements, and the interim unaudited condensed consolidated financial statements presented herein, have been prepared in accordance with U.S. GAAP, the requirements of Form 10-Q and Article 10 of Regulation S-X and, consequently, do not include all information or footnotes required by U.S. GAAP for complete financial statements or all the disclosures normally made in an Annual Report on Form 10-K. Accordingly, the unaudited condensed consolidated financial statements included herein should be read in conjunction with the audited consolidated financial statements and footnotes included in the Company’s 2022 Annual Report on Form 10-K filed with the United States Securities and Exchange Commission (“SEC”) on March 29, 2023. Reclassifications Certain reclassifications are made to prior year amounts whenever necessary to conform with the current year presentation. Certain reclassifications have been made to balances within the Condensed Consolidated Statements of Cash Flows for the nine months ended September 30, 2022 and Note 9: Other Assets and Liabilities for the year ended December 31, 2022 to condense line items of the same nature into a single line. We identified additional significant accounting policies as described below. Revenue. Revenue includes sales of LUMRYZ. ASC 606 applies to all contracts with customers, except for contracts that are within the scope of other standards, such as leases, insurance, collaboration arrangements and financial instruments. Under ASC 606, an entity recognizes revenue when the performance obligations to the customer have been satisfied through the transfer of control of the goods or services. To determine the appropriate revenue recognition for arrangements that the Company believes are within the scope of ASC 606, we perform the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the entity satisfies a performance obligation. The Company applies the five-step model to contracts only when the Company and its customer’s rights and obligations under the contract can be determined, the contract has commercial substance, and it is probable that the Company will collect the consideration it is entitled to in exchange for the goods or services it transfers to the customer. For contracts that are determined to be within the scope of ASC 606, the Company identifies the promised goods or services in the contract to determine if they are separate performance obligations or if they should be bundled with other goods and services into a single performance obligation. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) the performance obligation is satisfied. Product Sales The Company sells LUMRYZ to specialty pharmacies and considers those specialty pharmacies to be its customers. Under ASC 606, revenue from product sales is recognized when the customer obtains control of the product, which occurs typically upon receipt by the customer. The Company’s gross product sales are subject to a variety of price adjustments to arrive at reported net product revenue. These adjustments include estimates of payment discounts, specialty pharmacy fees, patient financial assistance programs, rebates and product returns and are estimated based on contractual arrangements, historical trends, expected utilization of such products and other judgments and analysis. Reserves for Variable Consideration Revenues from product sales are recorded at the estimated net selling price, which includes reserves for estimated variable consideration to reduce gross product sales to net product revenue resulting from payment discounts, specialty pharmacy fees, patient financial assistance programs, rebates and product returns. These reserves are based on the amounts earned or to be claimed on the related sales and are classified as reductions of accounts receivable if the amount is payable to the customer. The reserves are classified as a liability if the amount is payable to a party other than a customer. Where appropriate, these estimated reserves take into consideration relevant factors such as current contractual and statutory requirements, specific known market events and trends, industry data, historical trends, current and expected patient demand and forecasted customer buying and payment patterns. Overall, these reserves reflect our best estimates to reduce gross selling price to net selling price. The actual net selling price ultimately may differ from our estimates. Inventories. Inventories consist of raw materials, work in process and finished products, which are stated at lower of cost or net realizable value, using the first-in, first- out (“FIFO”) method. Raw materials used in the production of pre-clinical and clinical products are expensed as research and development (“R&D”) costs. The Company establishes reserves for inventory estimated to be obsolete, unmarketable or slow-moving on a case by case basis. The Company capitalizes inventory costs associated with products when future commercialization is considered probable and the future economic benefit is expected to be realized, which is typically when regulatory approval is obtained for a drug candidate. As such, the Company began capitalizing costs related to inventory in May 2023 upon FDA approval of LUMRYZ. Manufacturing costs associated with inventory purchased or produced prior to FDA approval were recorded as research and development expense in prior periods. Accordingly, cost of products sold in the near term will likely be lower than in later periods given the sales of pre-approval inventory will carry little to no manufacturing costs given such costs were previously expensed to research and development expense. The unaudited condensed consolidated financial statements include the accounts of the Company and subsidiaries and reflect all adjustments (consisting only of normal recurring adjustments) that are, in the opinion of management, necessary for a fair presentation of the Company’s financial position, results of operations and cash flows for the dates and periods presented. All intercompany accounts and transactions have been eliminated. Results for interim periods are not necessarily indicative of the results to be expected during the remainder of the current year or for any future period.