Business Organization	9 Months Ended
Business Organization	Sep. 30, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Business Organization	Business Organization Supernus Pharmaceuticals, Inc. (the Company) is a biopharmaceutical company focused on developing and commercializing products for the treatment of central nervous system (CNS) diseases. The Company's diverse neuroscience portfolio includes approved treatments for epilepsy, migraine, attention-deficit hyperactivity disorder (ADHD), hypomobility in Parkinson’s Disease (PD), cervical dystonia, chronic sialorrhea, dyskinesia in PD patients receiving levodopa-based therapy, and drug-induced extrapyramidal reactions in adult patients. The Company is developing a broad range of novel CNS product candidates including new potential treatments for hypomobility in PD, epilepsy, depression, and other CNS disorders. Commercial Products •Trokendi XR® (topiramate) is the first once-daily extended-release topiramate product indicated for the treatment of epilepsy in patients 6 years of age and older in the United States (U.S.) market. It is also indicated for the prophylaxis of migraine headache in adults and adolescents 12 years and older. •Oxtellar XR® (oxcarbazepine) is indicated as therapy for the treatment of partial onset seizures in patients 6 years of age and older. It is also the first once-daily extended-release oxcarbazepine product indicated for the treatment of epilepsy in the U.S. •Qelbree® (viloxazine extended-release capsules) is a novel non-stimulant product indicated for the treatment of ADHD in adults and pediatric patients 6 years and older. On April 2, 2021, the U.S. Food and Drug Administration (FDA) approved Qelbree for the treatment of ADHD in pediatric patients 6 to 17 years of age. In May 2021, the Company launched Qelbree for pediatric patients in the U.S. On April 29, 2022, the FDA approved Qelbree for treatment of ADHD in adult patients. The Company launched Qelbree for adult patients in May 2022. •GOCOVRI® (amantadine) extended-release capsules is the first and only FDA approved medicine indicated for the treatment of dyskinesia in patients with PD receiving levodopa-based therapy, with or without concomitant dopaminergic medications, and as an adjunctive treatment to levodopa/carbidopa with PD experiencing "off" episodes. •APOKYN® (apomorphine hydrochloride injection) is a product indicated for the acute, intermittent treatment of hypomobility, "off" episodes ("end-of-dose wearing off" and unpredictable "on/off" episodes) in patients with advanced PD. •XADAGO® (safinamide) is a once-daily product indicated as adjunctive treatment to levodopa/carbidopa in patients with PD experiencing "off" episodes. •Osmolex ER® (amantadine) extended-release is a once-daily product for the treatment of PD and drug-induced extrapyramidal reactions in adult patients. •MYOBLOC® (rimabotulinumtoxinB injection) is a product indicated for the treatment of cervical dystonia and chronic sialorrhea in adults. It is the only botulinum toxin type B available on the market. Product Candidates The Company is also developing a pipeline of novel CNS product candidates for the treatment of various CNS conditions. The Company's product candidates in clinical development include the following: •SPN-830 (apomorphine infusion device) is a late-stage drug/device combination product candidate for the continuous treatment of motor fluctuations ("off" episodes) in PD patients that are not adequately controlled with oral levodopa and one or more adjunct PD medications. In October 2022, the FDA issued a Complete Response Letter (CRL) regarding the NDA for SPN-830. Refer to Note 17, Subsequent Events. •SPN-820 (NV-5138) is a first-in-class product candidate for treatment-resistant depression, currently in Phase II development. It is an orally active small molecule that directly activates brain mechanistic target of rapamycin complex 1 (mTORC1). •SPN-817 (huperzine A) is a novel product candidate for treatment-resistant seizures, currently in Phase I development. Adamas Acquisition and Reorganization On October 10, 2021, the Company entered into an Agreement and Plan of Merger by and among the Company, Adamas Pharmaceuticals, Inc. (Adamas) and Supernus Reef, Inc., a Delaware corporation and a wholly owned subsidiary of the Company (Purchaser) (Adamas Agreement). On November 24, 2021 (the Closing Date), the Company completed its purchase of all of the outstanding equity of Adamas, pursuant to the Adamas Agreement dated October 10, 2021, and the Purchaser was merged with and into Adamas (the Merger), with Adamas continuing as the surviving corporation in the Merger as a wholly owned subsidiary of the Company (Adamas Acquisition). On the Closing Date, Adamas owned two marketed products: GOCOVRI (amantadine) extended-release capsules, the first and only FDA approved medicine indicated for the treatment of both "off" episodes and dyskinesia in patients with PD receiving levodopa-based therapy and as an adjunctive treatment to levodopa/carbidopa in patients with PD experiencing "off" episodes; and Osmolex ER (amantadine) extended-release tablets, approved for the treatment of PD and drug-induced extrapyramidal reactions in adult patients. Adamas also owns the right to receive royalties from Allergan plc for sales of Namzaric (memantine hydrochloride extended-release and donepezil hydrochloride) in the U.S. In the first quarter of 2022 and subsequent to the Adamas Acquisition, the Company completed a reorganization of the Adamas legal entities in an effort to obtain operational, legal and other benefits that also resulted in certain state tax efficiencies. The reorganization had no effect on the condensed consolidated financial statements other than certain state tax efficiencies. (See Note 12, Income Tax (Benefit) Expense.) COVID-19 Impact The Company is closely monitoring the impact of the COVID-19 pandemic on all aspects of its business operations and has assessed the impact of the COVID-19 pandemic on its condensed consolidated financial statements as of September 30, 2022. Since the situation surrounding the COVID-19 pandemic remains fluid and the duration uncertain, the long-term nature and extent of the impacts of the pandemic on the Company's business operations and financial position cannot be reasonably estimated at this time.