Collaboration, License and Purchase Agreements	12 Months Ended
Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Collaboration, License and Purchase Agreements	3. Collaboration, License and Purchase Agreements Zogenix International Limited Sales and Purchase Agreement In October 2014, the Company acquired Zogenix International Limited, pursuant to a sale and purchase agreement with Brabant Pharma Limited (Brabant). Zogenix International Limited owns worldwide development and commercialization rights to ZX008 (low-dose fenfluramine). Under the terms of the sale and purchase agreement, the Company agreed to make future milestone payments to the former principals of Brabant of up to $95.0 million in the event the Company achieves certain milestones with respect to ZX008, consisting of $50.0 million in regulatory milestones and $45.0 million in sales milestones. In addition, Zogenix International Limited has a collaboration and license agreement with the Universities of Antwerp and Leuven in Belgium (the Universities) that runs through September 2045. Under the terms of the agreement, the Universities granted Zogenix International Limited an exclusive worldwide license to use the data obtained from the study, as well as certain intellectual property related to fenfluramine for the treatment of Dravet syndrome. Zogenix International Limited is required to pay a mid-single-digit percentage royalty on net sales of fenfluramine for the treatment of Dravet syndrome or, in the case of a sublicense of fenfluramine for the treatment of Dravet syndrome, a percentage in the mid-twenties of the sub-licensing revenues. The agreement may be terminated by the Universities if Zogenix International Limited: (a) does not use commercially reasonable efforts to (i) develop and commercialize fenfluramine for the treatment of Dravet syndrome or related conditions stemming from infantile epilepsy, or (ii) seek approval of fenfluramine for the treatment of Dravet syndrome in the United States; or (b) if Zogenix International Limited becomes insolvent, shall make an assignment for the benefit of creditors, or shall have a petition in bankruptcy filed for or against it or if a petition for any similar relief has been filed against it. The Company can terminate the agreement upon specified prior written notice to the Universities. Endo Asset Purchase Agreement In May 2014, the Company completed the sale of its Sumavel DosePro business to Endo and concurrently entered into the Endo Supply Agreement for the exclusive right, and contractual obligation, to manufacture and supply Sumavel DosePro to Endo. The agreement provides for an initial term of eight years. In September 2017, the Endo Supply Agreement was terminated (See Note 6). Durect Development and License Agreement for Relday In July 2011, the Company entered into a development and license agreement with Durect under which the Company was granted an exclusive worldwide development and commercialization license to intellectual property related to Relday. Relday is an investigational, proprietary, long-acting formulation of risperidone, an atypical anti-psychotic agent. Under the development and license agreement, the Company were responsible for the clinical development and commercialization of Relday while Durect was responsible for pre-clinical, formulation and chemistry, manufacturing and controls development. In addition, the Company was obligated to use commercially reasonable efforts to fund the development and seek and maintain regulatory approval for Relday and if successful, to pay Durect up to $103.0 million in total future milestone payments with respect to Relday, subject to and upon the achievement of various development, regulatory, and sales-related milestones. In August 2017, the Company and Durect entered into an agreement to terminate the development and license agreement related to Relday. Under the terms of the termination agreement, all of our development and commercialization rights related to Relday were returned to Durect and all our regulatory filings and development information related to Relday will be assigned and/or transferred to Durect. Upon termination, the Company has no further obligations to make any potential future milestone payments with respect to Relday. In addition, the termination agreement does not provide the Company with any future royalty entitlements. Aradigm Corporation Asset Purchase Agreement In 2006, the Company entered into an asset purchase agreement with Aradigm Corporation (Aradigm). Under the terms of the agreement, Aradigm transferred all of its tangible assets and intellectual property related to the DosePro needle-free drug delivery system to the Company. Aradigm also granted the Company a non-exclusive license under all of its other intellectual property related to the DosePro delivery system prior to the closing of the asset purchase. Aradigm retained a non-exclusive license, with a right to sublicense, under all transferred intellectual property rights solely for purposes of the pulmonary field, and the Company granted Aradigm a license under other intellectual property rights solely for use in the pulmonary field. Endo pays royalties to Aradigm Corporation on sales of Sumavel DosePro subsequent to the sale of the business to Endo in May 2014. The Company made an initial payment to Aradigm at the closing of the asset purchase and made an additional milestone payment upon the U.S. commercialization of Sumavel DosePro in 2010. The Company is also required to pay a 3% royalty on global net sales of Sumavel DosePro, by the Company or one of the Company’s future licensees, if any, until the later of January 2020 or the expiration of the last valid claim of the transferred patents covering the manufacture, use, or sale of the product. The Company recorded the second milestone payment in other assets in the consolidated balance sheet and was amortizing the prepaid royalties over the estimated useful life of the technology to royalty expense. As a result of Endo’s decision to discontinue Sumavel DosePro (see Note 6), the Company recorded an impairment charge of $2.0 million to write off the remaining carrying amount of the prepaid royalties. The Company does not expect further royalty payments under this agreement as Sumavel DosePro has been discontinued. Other Asset Acquisitions In October 2016, the Company paid $1.5 million to acquire the global rights to a preclinical development program for orphan CNS disorders in an asset acquisition. At the date of acquisition, the project had not yet reached technological feasibility, was deemed to have no alternative use, and was immediately charged to research and development expense. The asset purchase agreement provides for potential additional payments if certain development and sales milestones are achieved. Due to the preclinical stage of development and the nature of this arrangement, any future potential payments related to the attainment of the specified milestones over a period of several years are inherently uncertain.

3. Collaboration, License and Purchase Agreements

Zogenix International Limited Sales and Purchase Agreement

In October 2014, the Company acquired Zogenix International Limited, pursuant to a sale and purchase agreement with Brabant Pharma Limited (Brabant). Zogenix International Limited owns worldwide development and commercialization rights to ZX008 (low-dose fenfluramine). Under the terms of the sale and purchase agreement, the Company agreed to make future milestone payments to the former principals of Brabant of up to $95.0 million in the event the Company achieves certain milestones with respect to ZX008, consisting of $50.0 million in regulatory milestones and $45.0 million in sales milestones.

In addition, Zogenix International Limited has a collaboration and license agreement with the Universities of Antwerp and Leuven in Belgium (the Universities) that runs through September 2045. Under the terms of the agreement, the Universities granted Zogenix International Limited an exclusive worldwide license to use the data obtained from the study, as well as certain intellectual property related to fenfluramine for the treatment of Dravet syndrome. Zogenix International Limited is required to pay a mid-single-digit percentage royalty on net sales of fenfluramine for the treatment of Dravet syndrome or, in the case of a sublicense of fenfluramine for the treatment of Dravet syndrome, a percentage in the mid-twenties of the sub-licensing revenues. The agreement may be terminated by the Universities if Zogenix International Limited: (a) does not use commercially reasonable efforts to (i) develop and commercialize fenfluramine for the treatment of Dravet syndrome or related conditions stemming from infantile epilepsy, or (ii) seek approval of fenfluramine for the treatment of Dravet syndrome in the United States; or (b) if Zogenix International Limited becomes insolvent, shall make an assignment for the benefit of creditors, or shall have a petition in bankruptcy filed for or against it or if a petition for any similar relief has been filed against it. The Company can terminate the agreement upon specified prior written notice to the Universities.

Endo Asset Purchase Agreement

In May 2014, the Company completed the sale of its Sumavel DosePro business to Endo and concurrently entered into the Endo Supply Agreement for the exclusive right, and contractual obligation, to manufacture and supply Sumavel DosePro to Endo. The agreement provides for an initial term of eight years. In September 2017, the Endo Supply Agreement was terminated (See Note 6).

Durect Development and License Agreement for Relday

In July 2011, the Company entered into a development and license agreement with Durect under which the Company was granted an exclusive worldwide development and commercialization license to intellectual property related to Relday. Relday is an investigational, proprietary, long-acting formulation of risperidone, an atypical anti-psychotic agent. Under the development and license agreement, the Company were responsible for the clinical development and commercialization of Relday while Durect was responsible for pre-clinical, formulation and chemistry, manufacturing and controls development. In addition, the Company was obligated to use commercially reasonable efforts to fund the development and seek and maintain regulatory approval for Relday and if successful, to pay Durect up to $103.0 million in total future milestone payments with respect to Relday, subject to and upon the achievement of various development, regulatory, and sales-related milestones.

In August 2017, the Company and Durect entered into an agreement to terminate the development and license agreement related to Relday. Under the terms of the termination agreement, all of our development and commercialization rights related to Relday were returned to Durect and all our regulatory filings and development information related to Relday will be assigned and/or transferred to Durect. Upon termination, the Company has no further obligations to make any potential future milestone payments with respect to Relday. In addition, the termination agreement does not provide the Company with any future royalty entitlements.

Aradigm Corporation Asset Purchase Agreement

In 2006, the Company entered into an asset purchase agreement with Aradigm Corporation (Aradigm). Under the terms of the agreement, Aradigm transferred all of its tangible assets and intellectual property related to the DosePro needle-free drug delivery system to the Company. Aradigm also granted the Company a non-exclusive license under all of its other intellectual property related to the DosePro delivery system prior to the closing of the asset purchase. Aradigm retained a non-exclusive license, with a right to sublicense, under all transferred intellectual property rights solely for purposes of the pulmonary field, and the Company granted Aradigm a license under other intellectual property rights solely for use in the pulmonary field. Endo pays royalties to Aradigm Corporation on sales of Sumavel DosePro subsequent to the sale of the business to Endo in May 2014.

The Company made an initial payment to Aradigm at the closing of the asset purchase and made an additional milestone payment upon the U.S. commercialization of Sumavel DosePro in 2010. The Company is also required to pay a 3% royalty on global net sales of Sumavel DosePro, by the Company or one of the Company’s future licensees, if any, until the later of January 2020 or the expiration of the last valid claim of the transferred patents covering the manufacture, use, or sale of the product. The Company recorded the second milestone payment in other assets in the consolidated balance sheet and was amortizing the prepaid royalties over the estimated useful life of the technology to royalty expense. As a result of Endo’s decision to discontinue Sumavel DosePro (see Note 6), the Company recorded an impairment charge of $2.0 million to write off the remaining carrying amount of the prepaid royalties. The Company does not expect further royalty payments under this agreement as Sumavel DosePro has been discontinued.

Other Asset Acquisitions

In October 2016, the Company paid $1.5 million to acquire the global rights to a preclinical development program for orphan CNS disorders in an asset acquisition. At the date of acquisition, the project had not yet reached technological feasibility, was deemed to have no alternative use, and was immediately charged to research and development expense. The asset purchase agreement provides for potential additional payments if certain development and sales milestones are achieved. Due to the preclinical stage of development and the nature of this arrangement, any future potential payments related to the attainment of the specified milestones over a period of several years are inherently uncertain.