Summary of Significant Accounting Policies and Basis of Presentation | 1. Summary of significant accounting policies and basis of presentation Organization and Share Exchange Albireo Pharma, Inc. (Parent), together with its direct and indirect subsidiaries (the Company), is a clinical-stage biopharmaceutical company focused on the development and commercialization of novel bile acid modulators to treat orphan pediatric liver diseases and other liver and gastrointestinal diseases and disorders. The Company’s clinical pipeline includes two Phase 2 product candidates, plus a third product candidate for which an application for regulatory approval has been filed in Japan. A4250, the Company’s lead product candidate, is in development initially for the treatment of progressive familial intrahepatic cholestasis (PFIC), a rare, life-threatening genetic disorder affecting young children. Prior to November 3, 2016, Parent’s name was Biodel Inc. (Biodel). On that date, Biodel effected a 1-for-30 reverse stock split of its common stock (Reverse Stock Split) and completed a share exchange transaction with Albireo Limited, a limited company domiciled in London, United Kingdom, in accordance with the terms of an Amended and Restated Share Exchange Agreement, dated as of July 13, 2016, by and among Biodel, Albireo Limited and the shareholders and noteholders of Albireo Limited (the Agreement). Pursuant to the Agreement, each holder of shares or notes convertible into shares of Albireo Limited received newly issued shares of Biodel common stock and Albireo Limited became a wholly owned subsidiary of Biodel (the Transaction). Following completion of the Transaction, the business of Albireo Limited became the business of Parent and Parent changed its name to Albireo Pharma, Inc. For accounting purposes, the Transaction was treated as a “reverse acquisition” and Albireo Limited was considered the accounting acquirer. Accordingly, with respect to periods prior to completion of the Transaction, the accompanying Condensed Consolidated Financial Statements reflect the historical results of Albireo Limited and its direct and indirect subsidiaries and do not include the historical results of Biodel prior to completion of the Transaction. All share and per share information for periods prior to completion of the Transaction has been retroactively adjusted to reflect the exchange of shares in the Transaction based on an exchange ratio of 0.06999 and, where applicable, the Reverse Stock Split. Basis of presentation The accompanying unaudited Condensed Consolidated Financial Statements have been prepared in accordance with U.S. generally accepted accounting principles (GAAP) for interim financial information, the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements and should be read in conjunction with the audited consolidated financial statements and accompanying notes included in Parent’s Annual Report on Form 10-K for the fiscal year ended December 31, 2016. In the opinion of management, all adjustments (including normal recurring accruals) considered necessary for fair presentation have been included in the Condensed Consolidated Financial Statements. The results of operations for the three months ended March 31, 2017 are not necessarily indicative of the results that may be expected for the full fiscal year, any other interim period or any future fiscal year. Any reference in these notes to applicable guidance is meant to refer to the authoritative GAAP as found in the Accounting Standards Codification (ASC) and Accounting Standards Update (ASU) of the Financial Accounting Standards Board (FASB). Any reference in these Condensed Consolidated Financial Statements to common stock or options or warrants to purchase shares of common stock of the Company means the common stock or options or warrants to purchase shares of common stock of Parent. Any reference in these Condensed Consolidated Financial Statements to common stock means, for periods prior to November 3, 2016, Ordinary shares of Albireo Limited. The Company has reclassified certain amounts in the Condensed Consolidated Balance Sheet as of December 31, 2016 from Advances from licensees and from Common stock warrant liability to Other liabilities to conform to the current year presentation. Principles of consolidation The accompanying Condensed Consolidated Financial Statements include the accounts of Parent and its direct or indirect wholly owned subsidiaries, Albireo Limited, Albireo AB, Elobix AB, Albireo, Inc and, for periods following completion of the Transaction, Biodel UK Limited. All intercompany balances and transactions have been eliminated in consolidation. Foreign currency translation Functional and presentation currency Items included in the financial statements of each entity comprising the Company are measured using the currency of the primary economic environment in which the entity operates (the functional currency). The functional currency for Parent and Albireo, Inc. is the U.S. Dollar (USD), the functional currency for Albireo Limited, Elobix AB and Biodel U.K. is the Euro, and the functional currency for Albireo AB is the Swedish Krona (SEK). The Company consolidates its financial statements in USD. Transactions and balances Foreign currency transactions in each entity comprising the Company are remeasured into the functional currency of the entity using the exchange rates prevailing at the respective transaction dates. Foreign exchange gains and losses resulting from the settlement of such transactions and from the translation at period-end exchange rates of monetary assets and liabilities denominated in foreign currencies are recognized within Other income (expense), net in the Condensed Consolidated Statements of Operations. The results and financial position of the Company and its subsidiaries that have a functional currency different from the presentation currency are translated into the presentation currency as follows: a. assets and liabilities presented are translated at the closing exchange rate as of March 31, 2017 and December 31, 2016; b. income and expenses for each statement of comprehensive loss are translated at the average exchange rates that are relevant for the period reported; c. significant transactions use the closing exchange rate on the date of the transaction; and d. all resulting exchange differences arising from such translation are recognized directly in other comprehensive loss and presented as a separate component of equity. Use of estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts of assets, liabilities, revenues and expenses reported in the financial statements and accompanying notes. Management must apply significant judgment in this process. On an ongoing basis, the Company evaluates its estimates and assumptions, including but not limited to accruals, deferred tax assets and warrant liability estimated at fair value. Actual results could materially differ from these estimates. Research and development expenses Research and development costs are expensed as incurred and include primarily salaries, benefits and other staff-related costs; clinical trial and related clinical manufacturing costs; contract services and other outside costs. The Company’s preclinical studies and clinical trials are performed by third-party contract research organizations (CROs). Some of these expenses are billed monthly for services performed, while others are billed based upon milestones achieved. For preclinical studies, the significant factors used in estimating accruals include the percentage of work completed to date and contract milestones achieved. For clinical trial expenses, the significant factors used in estimating accruals include the number of patients enrolled and percentage of work completed to date or contract milestones achieved. The Company’s estimates are highly dependent upon the timeliness and accuracy of the data provided by the respective CROs regarding the status of the contracted activity, with adjustments made when deemed necessary. Revenue recognition Revenue is generated from the receipt of upfront or license fees, milestone payments and payments for pharmaceutical ingredient or related procurement services that are made pursuant to out-licensing or related supply agreements. Where an out-licensing arrangement of the Company involves the provision of multiple elements that may contain different remuneration arrangements such as upfront payments, milestone payments or product sales, the arrangement is assessed to determine whether separate delivery of the individual elements of such arrangement comprises more than one unit of accounting. The delivered elements are separated if (a) they have value to the licensee on a stand-alone basis, (b) there is objective and reliable evidence of the fair value of the undelivered element(s) and (c) if the arrangement includes a general right of return relative to the delivered element(s), delivery or performance of the undelivered element(s) is considered probable and is substantially in the control of the Company. Allocation of revenue to the different elements that require separate accounting is based on the separate selling prices determined for each component, and total consideration is then allocated pro rata across the components of the arrangement. If separate selling prices are not available, the Company will use its best estimate of such selling prices, consistent with the overall pricing strategy and relevant market factors. The Company has determined that each element of its out-licensing agreements is a separate and distinct unit of accounting, and, as such, the fair value of each element has been subscribed and recognized as follows: • Nonrefundable upfront payments received from the Company’s out-licensing agreements relating to technical expertise and intellectual property are recognized in income if all rights relating to the intellectual property and all obligations resulting from them have been relinquished under the contract terms and the Company has no continuing material obligation to perform under the agreement. However, if rights to the intellectual property continue to exist or obligations resulting from them have yet to be fulfilled, the payments received would be deferred until all rights and obligations have been fulfilled. • Nonrefundable payments that are linked to the achievement of significant and substantive development or regulatory milestones in the research and development process are recognized as revenue upon the achievement of the specified milestone. • Revenue and costs associated with procurement services associated with pharmaceutical ingredients are recognized net in revenue when title and risk of loss of the pharmaceutical ingredients have passed to the licensee as the Company is not the primary obligor and revenue and costs associated with related procurement services are recognized net in revenue when the Company is contractually bound. As of March 31, 2017, the Company had a license agreement with EA Pharma Co., Ltd. (EA Pharma, formerly Ajinomoto Pharmaceuticals Co., Ltd.), entered into in 2012, to develop a select product candidate (elobixibat) for registration and subsequent commercialization in select markets. The Company satisfied its material performance obligations under the agreement in 2012, upon the delivery of technical expertise and intellectual property rights to EA Pharma. Payments resulting from pharmaceutical ingredient or related procurement services are recognized as revenue as the activities are performed and are presented on a net basis. Revenue is recorded on a net basis because the Company acts as an agent, as it does not have discretion to change suppliers and does not perform any part of the services or manufacture of the subject pharmaceutical ingredients. The costs associated with these activities are netted against the related revenue in the Condensed Consolidated Statements of Operations. For certain contingent payments under research and development arrangements, the Company recognizes revenue using the milestone method. Under the milestone method, a payment that is contingent upon the achievement of a substantive milestone is recognized in its entirety in the period in which the milestone is achieved. A milestone is an event: (i) that can be achieved based in whole or in part on either the Company’s performance or on the occurrence of a specific outcome resulting from the Company’s performance, (ii) for which there is substantive uncertainty at the date the arrangement is entered into that the event will be achieved and (iii) that would result in additional payments being due to the Company. The determination that a milestone is substantive requires estimation and judgment and is made at the inception of the arrangement. Milestones are considered substantive when the consideration earned from the achievement of the milestone is: (A) commensurate with either the Company’s performance to achieve the milestone or the enhancement of value of the item delivered as a result of a specific outcome resulting from the Company’s performance to achieve the milestone, (B) related solely to past performance and (C) reasonable relative to all deliverables and payment terms in the arrangement. In making the determination as to whether a milestone is substantive or not, management of the Company considers all facts and circumstances relevant to the arrangement, including factors such as the scientific, regulatory, commercial and other risks that must be overcome to achieve the milestone, the level of effort and investment required to achieve the milestone and whether any portion of the milestone consideration is related to future performance or deliverables. The Company has evaluated each milestone specified under its license agreement with EA Pharma and determined the milestone to be substantive. Under the terms of the license agreement with EA Pharma, the Company was eligible as of March 31, 2017 to receive up to approximately (a) €13.3 million ($14.2 million based on the Euro to USD exchange rate as of March 31, 2017) if specified regulatory events are achieved for elobixibat in Japan and (b) ¥3.5 billion ($31.4 million based on the Japanese Yen to USD exchange rate as of March 31, 2017) if specified sales milestones are achieved for elobixibat following regulatory approval in any country in EA Pharma’s licensed territory. The likelihood that the Company will achieve any particular milestone event with respect to elobixibat in any particular period, or at all, is uncertain, and the Company may not earn any future milestone payment with respect to elobixibat in any particular period, or ever. In addition, the Company is eligible to receive stepped royalties beginning in the high single digits on any future elobixibat product sales. The Company will recognize royalty revenue in the period of sale of elobixibat, based on the underlying contract terms, provided that the reported sales are reliably measurable and the Company has no remaining performance obligations, assuming all other revenue recognition criteria are met. Loss contingencies Loss contingencies are recorded as liabilities when it is probable that a liability has occurred and the amount of loss is reasonably estimable. Disclosure is required when there is a reasonable possibility that an ultimate loss will be material. Contingent liabilities are often resolved over long periods of time. Estimating probable losses requires analysis that often depends on judgments about potential actions by third parties, such as regulators. Recently adopted accounting pronouncements In March 2016, the FASB issued ASU No. 2016-09, “ Compensation—Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting Accounting pronouncements issued but not yet adopted In May 2014, the FASB issued ASU No. 2014-09, “ Revenue from Contracts with Customers: (Topic 606) Revenue Recognition Property, Plant, and Equipment Intangibles-Goodwill and Other consolidated In February 2016, the FASB issued ASU 2016-02, “ Leases (Topic 842) In September 2016, the FASB issued ASU 2016-15, “ Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments (a consensus of the Emerging Issues Task Force) |