Summary of Significant Accounting Policies	9 Months Ended
Summary of Significant Accounting Policies	Sep. 30, 2022
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Presentation The Company’s unaudited condensed consolidated financial statements have been prepared in accordance with the requirements of the U.S. Securities and Exchange Commission (SEC) for interim financial information. As permitted under Generally Accepted Accounting Principles in the United States (U.S. GAAP), certain notes and other information have been omitted from the interim unaudited condensed consolidated financial statements presented in this Quarterly Report on Form 10-Q. Therefore, these condensed consolidated financial statements should be read in conjunction with the Company’s most recent Annual Report on Form 10-K, for the year ended December 31, 2021, filed with the SEC. In management’s opinion, the condensed consolidated financial statements include all normal and recurring adjustments necessary for a fair presentation of the Company’s financial position, results of operations, and cash flows. The results of operations for any interim period are not necessarily indicative of the Company’s future quarterly or annual results. The Company, which is primarily located in the U.S., operates in one operating segment. Consolidation The Company's condensed consolidated financial statements include the accounts of Supernus Pharmaceuticals, Inc. and its wholly owned subsidiaries. These are collectively referred to herein as "Supernus" or "the Company." All significant intercompany transactions and balances have been eliminated in consolidation. The consolidated financial statements reflect the consolidation of entities in which the Company has a controlling financial interest. In determining whether there is a controlling financial interest, the Company considers if it has a majority of the voting interests of the entity, or if the entity is a variable interest entity (VIE) and if the Company is the primary beneficiary. In determining the primary beneficiary of a VIE, the Company evaluates whether it has both: the power to direct the activities of the VIE that most significantly impact the VIE's economic performance; and the obligation to absorb losses of, or the right to receive benefits from the VIE that could potentially be significant to that VIE. The Company's judgment with respect to its level of influence or control of an entity involves the consideration of various factors, including the form of an ownership interest; representation in the entity's governance; the size of the investment; estimates of future cash flows; the ability to participate in policymaking decisions; and the rights of the other investors to participate in the decision making process, including the right to liquidate the entity, if applicable. If the Company is not the primary beneficiary of the VIE, and an ownership interest is maintained in the entity, the interest is accounted for under the equity or cost methods of accounting, as appropriate. The Company continuously assesses whether it is the primary beneficiary of a VIE as changes to existing relationships or future transactions may affect its conclusions. Use of Estimates The Company bases its estimates on: historical experience; forecasts; information received from its service providers; information from other sources, including public and proprietary sources; and other assumptions that the Company believes are reasonable under the circumstances. Actual results could differ materially from the Company’s estimates. The Company periodically evaluates the methodologies employed in making its estimates. The extent to which the COVID-19 pandemic may directly or indirectly impact our business, financial condition and results of operations is highly uncertain and subject to change. As a result, certain of our estimates and assumptions, including the provision for sales deductions, the fair values of financial instruments and the recoverability of intangible assets, require increased judgment and carry a higher degree of variability and volatility that could result in material changes to our estimates in future periods. Advertising Expense Advertising expense includes the cost of promotional materials and activities, such as television, print media, digital marketing, marketing programs and speaker programs. The cost of the Company's advertising efforts are expensed as incurred. The Company incurred approximately $52.0 million and $112.8 million in advertising expense for the three and nine months ended September 30, 2022, respectively, and approximately $22.6 million and $59.7 million for the three and nine months ended September 30, 2021, respectively. These expenses are recorded as a component of Selling, general and administrative expenses in the condensed consolidated statements of earnings. Recently Issued Accounting Pronouncements Accounting Pronouncements Adopted Accounting Standards Update (ASU) 2020-06, Debt - Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging - Contracts in Entity's Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity's Own Equity - The new standard, issued in August 2020, simplifies the accounting for certain financial instruments with characteristics of liabilities and equity, including convertible debt instruments with cash conversion and beneficial conversion features. ASU 2020-06 eliminates requirements to separately account for liability and equity components of such convertible debt instruments and eliminates the ability to use the treasury stock method for calculating diluted earnings per share for convertible instruments whose principal amount may be settled in whole or in part with equity. Instead, ASU 2020-06 requires (i) the entire amount of the security to be presented as a liability on the balance sheet and (ii) application of the “if-converted” method for calculating diluted earnings per share. This new standard also removes certain settlement conditions required for equity contracts to qualify for the derivative scope exception. The Company adopted the new guidance as of January 1, 2022 using the modified retrospective method of transition which allows for a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption. As a result, the cumulative effect of the accounting change increased the carrying amount of the convertible notes, net by $20.6 million, increased retained earnings by $40.6 million, reduced additional paid-in capital by $56.2 million, and decreased deferred tax liabilities by $5.0 million as of January 1, 2022. In addition, the Company had an increase of 6.8 million in dilutive shares included in diluted weighted average shares of common stock outstanding for the purposes of calculating diluted earnings per share under the if-converted method. ASU 2021-10, Government Assistance (Topic 832) - The new standard, issued in November 2021, requires the disclosure of information about transactions with a government that are accounted for by applying a grant or contribution model by analogy. This could include various forms of government assistance, but excludes transactions in the scope of specific U.S. GAAP, such as tax incentives accounted for under Accounting Standards Codification (ASC) 740, Income Taxes. For transactions in the scope of the new standard, information about the nature of the transaction, including significant terms and conditions, as well as the amounts and specific financial statement line items affected by the transaction are required to be disclosed. This guidance is effective for fiscal years beginning after December 15, 2021 on a prospective basis. The adoption of the new standard as of January 1, 2022 did not have a material impact to the financial statements.