License and Collaboration Agreements	12 Months Ended
Dec. 31, 2020
Business Combinations [Abstract]
Commitments and Contingencies	Under the terms of the following license and collaboration agreements, we may be required to make milestone payments upon achievement of certain development and regulatory activities of up to $8.5 billion and pay royalties on future sales, if any, of commercial products resulting from these agreements.
License and Collaboration Agreements	License and Collaboration Agreements Takeda Pharmaceutical Company Limited. We entered into an exclusive license agreement with Takeda Pharmaceutical Company Limited, or Takeda, which became effective in July 2020, to develop and commercialize certain compounds in Takeda’s early to mid-stage psychiatry pipeline. Specifically, Takeda granted us an exclusive license to the following seven assets: (i) NBI-1065844 (TAK-831) for schizophrenia, (ii) NBI-1065845 (TAK-653) for treatment-resistant depression, (iii) NBI-1065846 (TAK-041) for anhedonia (which together with the NBI-1065845 are referred to as the Phase II Ready Assets), and (iv) four non-clinical stage assets, or the Non-Clinical Assets. NBI-1065844 is deemed a royalty-bearing product under the license agreement pursuant to which we will be responsible for all costs and expenses associated with the development, manufacture, and commercialization of such asset, subject to certain exceptions, and Takeda will be eligible to receive development and commercial milestones and royalties with respect to such asset, or a Royalty-Bearing Product, and Takeda will retain the right to opt-in to a profit sharing arrangement pursuant to which we and Takeda will equally share in the operating profits and losses related to such asset, subject to certain exceptions, in lieu of receiving milestones and royalties, or a Profit-Share Product. Subject to specified conditions, Takeda may elect to exercise such opt-in right for NBI-1065844 before we initiate a Phase III clinical trial. Each of the Phase II Ready Assets is deemed a Profit-Share Product and Takeda will retain the right to opt-out of the profit-sharing arrangement for such asset pursuant to which such asset would become a Royalty-Bearing Product. Takeda may elect to exercise such opt-out rights with respect to a Phase II Ready Asset immediately following the completion of the second Phase II clinical trial for such Phase II Ready Asset. In addition, under certain circumstances related to the development and commercialization activities to be performed by us, Takeda may elect to opt-out of the profit-sharing arrangement for a Profit-Share Product before the initiation of a Phase III clinical trial for such product. Each of the Non-Clinical Assets will be Royalty-Bearing Products pursuant to which we will be responsible for all costs and expenses associated with the development, manufacture, and commercialization of such assets, subject to certain exceptions. In connection with the agreement, we paid Takeda $120.0 million upfront, which, including certain transaction related costs, was expensed as in-process research and development, or IPR&D, in the third quarter of 2020. Pursuant to the terms of the agreement, Takeda may also be entitled to receive additional payments of up to $1.9 billion upon the achievement of certain event-based milestones associated with Royalty-Bearing Products, as well as receive royalties on the future net sales of Royalty-Bearing Products. On a country-by-country and product-by-product basis, royalty payments would commence on the first commercial sale of a Royalty-Bearing Product and terminate on the later of (i) the expiration of the last patent covering such Royalty-Bearing Product in such country, (ii) a number of years from the first commercial sale of such Royalty-Bearing Product in such country and (iii) the expiration of regulatory exclusivity for Royalty-Bearing Product in such country. Idorsia Pharmaceuticals Ltd. In May 2020, we entered a collaboration and licensing agreement with Idorsia Pharmaceuticals Ltd, or Idorsia, to license the global rights to NBI-827104 (ACT-709478), a potent, selective, orally active and brain penetrating T-type calcium channel blocker, in clinical development for the treatment of a rare pediatric epilepsy. The agreement also includes a research collaboration to discover and identify additional novel T-type calcium channel blockers as development candidates. In connection with the exercise of the option, we paid Idorsia $45.0 million upfront, which we expensed as IPR&D in the second quarter of 2020. Further, as part of the research collaboration, we provided Idorsia with an incremental $7.2 million in funding, which we recorded as a prepaid asset and is being expensed over the two-year research collaboration term. Pursuant to the terms of the agreement, upon the achievement of certain development and regulatory milestones, Idorsia may be entitled to receive additional payments of up to $365.0 million with respect to NBI-827104 and $620.0 million with respect to the development candidates. Idorsia may also be entitled to receive additional payments of up to $750.0 million upon the achievement of certain commercial milestones, as well as receive royalties on the future net sales of any collaboration product. Further, we will be responsible for all manufacturing, development and commercialization costs of any collaboration product. Xenon Pharmaceuticals, Inc. In December 2019, we entered into a license and collaboration agreement with Xenon Pharmaceuticals Inc., or Xenon, to identify, research, and develop sodium channel inhibitors, including clinical candidate NBI-921352 (XEN901) and three preclinical candidates, which compounds we will have the exclusive right to further develop and commercialize under the terms and conditions set forth in the agreement. We will be solely responsible, at our sole cost and expense, for all development and manufacturing of the compounds and any pharmaceutical product that contains a compound, subject to Xenon’s right to elect to co-fund the development of one product in a major indication and thus receive a mid-single digit percentage increase in royalties owed on the net sales of such product in the U.S. If Xenon exercises such option, the parties will share equally all reasonable and documented costs and expenses incurred in connection with the development of such product in the applicable indication, except costs and expenses that are solely related to the development of such product for regulatory approval outside the U.S. In connection with the agreement, we paid Xenon $30.0 million upfront and purchased $20.0 million of Xenon’s common stock at $14.196 per share, representing approximately 1.4 million shares. Pursuant to the terms of the agreement, Xenon may also be entitled to receive additional payments of up to $1.7 billion upon the achievement of certain event-based milestones, as well as receive royalties on the future net sales of any collaboration product. We accounted for the transaction as an asset acquisition as the set of acquired assets did not constitute a business. Our equity investment in Xenon was recorded at a fair value of $14.1 million after considering Xenon’s stock price on the date of closing and certain lock-up and voting provisions applicable to the acquired shares. The remaining $36.2 million of the purchase price, which includes the applicable transaction costs, was expensed as IPR&D in the fourth quarter of 2019. Voyager Therapeutics, Inc. We entered into a collaboration and license agreement with Voyager Therapeutics, Inc., or Voyager, which became effective in March 2019, to develop and commercialize four programs using Voyager’s proprietary gene therapy platform. The four programs consist of the NBIb-1817 (VY-AADC) program for Parkinson’s disease, the Friedreich’s ataxia program and the rights to two undisclosed programs. In connection with the agreement, we paid Voyager $115.0 million upfront and purchased $50.0 million of Voyager’s common stock at $11.9625 per share, representing approximately 4.2 million shares. Pursuant to the terms of the agreement, Voyager may also be entitled to receive additional payments of up to $1.7 billion upon the achievement of certain event-based milestones, as well as receive royalties on the future net sales of any collaboration product. Pursuant to development plans agreed to by us and Voyager, unless Voyager exercises its co-development and co-commercialization rights as provided for in the agreement, we will be responsible for all development costs. Further, upon the occurrence of a specified event for each program, we will assume responsibility for the development, manufacturing, and commercialization activities of such program. We accounted for the transaction as an asset acquisition as the set of acquired assets did not constitute a business. Our equity investment in Voyager was recorded at a fair value of $54.7 million after considering Voyager’s stock price on the date of closing and certain lock-up and voting provisions applicable to the acquired shares. The remaining $113.1 million of the purchase price, which includes the applicable transaction costs, was expensed as in-process research and development, or IPR&D, in the first quarter of 2019. In June 2019, we entered into an amendment to the collaboration and license agreement with Voyager. Under the terms of the amendment, we paid Voyager $5.0 million upfront to obtain rights outside the U.S. to the Friedreich’s ataxia program in connection with the early return of those rights to Voyager pursuant to a restructuring of Voyager’s gene therapy relationship with Sanofi Genzyme. The upfront payment was expensed as IPR&D in the second quarter of 2019. BIAL – Portela & Ca, S.A. We acquired the U.S. and Canada rights to ONGENTYS® from BIAL in the first quarter of 2017. We launched ONGENTYS in the U.S. in September 2020, after receiving FDA approval for ONGENTYS as an adjunctive therapy to levodopa/DOPA decarboxylase inhibitors in adult Parkinson's disease patients in April 2020. FDA approval for ONGENTYS for Parkinson’s disease resulted in a $20.0 million event-based payment to BIAL, which we expensed as R&D in the second quarter of 2020. We further recognized R&D expense of $10.0 million in each 2019 and 2018 in connection with BIAL’s achievement of certain regulatory event-based milestones related to then ongoing development of ONGENTYS. Pursuant to the terms of the agreement, BIAL may also be entitled to receive additional payments of up to $75.0 million upon the achievement of certain event-based milestones. Under the terms of the agreement, we are responsible for the commercialization of ONGENTYS in the U.S. and Canada. Further, we rely on BIAL for the commercial supply of ONGENTYS. Upon our written request prior to the estimated expiration of the term of a licensed product, the parties shall negotiate a good faith continuation of BIAL’s supply of such licensed product after the term. After the term, and if BIAL is not supplying a certain licensed product, we shall pay BIAL a trademark royalty based on the net sales of such licensed product. Upon commercialization of ONGENTYS, we determined certain annual sales forecasts. In the event we fail to meet the minimum sales requirements for a particular year, we would be obligated to pay BIAL an amount equal to the difference between the actual net sales and minimum sales requirements for such year. Mitsubishi Tanabe Pharma Corporation. In March 2015, we entered into a collaboration and license agreement with Mitsubishi Tanabe Pharma Corporation, or MTPC, for the development and commercialization of INGREZZA for movement disorders in Japan and other select Asian markets. Since inception of the agreement, we have recognized revenue of $19.8 million associated with the delivery of a technology license and existing know-how and $15.0 million associated with the achievement of a certain event-based milestone. We further recognized revenue of $2.7 million in 2020 and $0.9 million in 2019 in connection with the ongoing KINECT-HD study, a placebo-controlled Phase III study of valbenazine in adult Huntington’s disease patients with chorea. In accordance with our continuing performance obligations, $6.7 million of the $30.0 million upfront payment received from MTPC is being deferred and will be recognized as revenue over the ongoing study period using an input method according to costs incurred to-date relative to estimated total costs associated with the study. Pursuant to the terms of the agreement, we may also be entitled to receive additional payments of up to $70.0 million upon the achievement of certain event-based milestones, receive payments for the manufacture of certain pharmaceutical products, as well as receive royalties on the future net sales of any collaboration product in select territories in Asia. Under the terms of the agreement, MTPC is responsible for all third-party development, marketing, and commercialization costs in Japan and other select Asian markets and we would be entitled to a percentage of sales of INGREZZA in Japan and other select Asian markets for the longer of ten years or the life of the related patent rights. Further, the collaboration effort between the parties to advance INGREZZA towards commercialization in Japan and other select Asian markets is governed by joint steering and development committees with representatives from both parties. AbbVie Inc. In June 2010, we entered into an exclusive worldwide collaboration with AbbVie Inc., or AbbVie, to develop and commercialize elagolix and all next-generation gonadotropin-releasing factor, or GnRH, antagonists and collectively, GnRH Compounds, for women’s and men’s health. AbbVie received approval for ORILISSA for the management of moderate to severe endometriosis pain in women from the FDA in July 2018 and Health Canada in October 2018. In May 2020, AbbVie received FDA approval for ORIAHNN for the management of heavy menstrual bleeding associated with uterine fibroids in pre-menopausal women. We recognized sales-based royalties on AbbVie net sales of ORILISSA and ORIAHNN of $19.2 million in 2020, $14.3 million in 2019 and $1.6 million in 2018. FDA approval for ORIAHNN for uterine fibroids resulted in the achievement of a $30.0 million event-based milestone, which we recognized as collaboration revenue in the second quarter of 2020. In 2019, we recognized collaboration revenue of $20.0 million in connection with the FDA’s acceptance of AbbVie’s NDA submission for the approval of ORIAHNN for uterine fibroids. In 2018, we recognized collaboration revenue of $40.0 million in connection with the FDA’s approval for ORILISSA for endometriosis. Since inception of the agreement, we have recognized revenue of $75.0 million associated with the delivery of a technology license and existing know-how and $165.0 million associated with the achievement of certain event-based milestones. Pursuant to the terms of the agreement, we may also be entitled to receive additional payments of up to $366.0 million upon the achievement of certain event-based milestones. Under the terms of the agreement, AbbVie is responsible for all third-party development, marketing, and commercialization costs. We are entitled to a percentage of worldwide sales of GnRH Compounds for the longer of ten years or the life of the related patent rights.
Subsequent Events	On February 2, 2021, we notified Voyager of our termination of the NBIb-1817 for Parkinson’s disease program. The effective date of this termination will be August 2, 2021. The termination does not apply to any other development program other than NBIb-1817 for Parkinson’s disease, and our collaboration and license agreement with Voyager will otherwise continue in effect.

Takeda Pharmaceutical Company Limited. We entered into an exclusive license agreement with Takeda Pharmaceutical Company Limited, or Takeda, which became effective in July 2020, to develop and commercialize certain compounds in Takeda’s early to mid-stage psychiatry pipeline. Specifically, Takeda granted us an exclusive license to the following seven assets: (i) NBI-1065844 (TAK-831) for schizophrenia, (ii) NBI-1065845 (TAK-653) for treatment-resistant depression, (iii) NBI-1065846 (TAK-041) for anhedonia (which together with the NBI-1065845 are referred to as the Phase II Ready Assets), and (iv) four non-clinical stage assets, or the Non-Clinical Assets.

NBI-1065844 is deemed a royalty-bearing product under the license agreement pursuant to which we will be responsible for all costs and expenses associated with the development, manufacture, and commercialization of such asset, subject to certain exceptions, and Takeda will be eligible to receive development and commercial milestones and royalties with respect to such asset, or a Royalty-Bearing Product, and Takeda will retain the right to opt-in to a profit sharing arrangement pursuant to which we and Takeda will equally share in the operating profits and losses related to such asset, subject to certain exceptions, in lieu of receiving milestones and royalties, or a Profit-Share Product. Subject to specified conditions, Takeda may elect to exercise such opt-in right for NBI-1065844 before we initiate a Phase III clinical trial. Each of the Phase II Ready Assets is deemed a Profit-Share Product and Takeda will retain the right to opt-out of the profit-sharing arrangement for such asset pursuant to which such asset would become a Royalty-Bearing Product. Takeda may elect to exercise such opt-out rights with respect to a Phase II Ready Asset immediately following the completion of the second Phase II clinical trial for such Phase II Ready Asset. In addition, under certain circumstances related to the development and commercialization activities to be performed by us, Takeda may elect to opt-out of the profit-sharing arrangement for a Profit-Share Product before the initiation of a Phase III clinical trial for such product.

In connection with the agreement, we paid Takeda $120.0 million upfront, which, including certain transaction related costs, was expensed as in-process research and development, or IPR&D, in the third quarter of 2020. Pursuant to the terms of the agreement, Takeda may also be entitled to receive additional payments of up to $1.9 billion upon the achievement of certain event-based milestones associated with Royalty-Bearing Products, as well as receive royalties on the future net sales of Royalty-Bearing Products. On a country-by-country and product-by-product basis, royalty payments would commence on the first commercial sale of a Royalty-Bearing Product and terminate on the later of (i) the expiration of the last patent covering such Royalty-Bearing Product in such country, (ii) a number of years from the first commercial sale of such Royalty-Bearing Product in such country and (iii) the expiration of regulatory exclusivity for Royalty-Bearing Product in such country.

Idorsia Pharmaceuticals Ltd. In May 2020, we entered a collaboration and licensing agreement with Idorsia Pharmaceuticals Ltd, or Idorsia, to license the global rights to NBI-827104 (ACT-709478), a potent, selective, orally active and brain penetrating T-type calcium channel blocker, in clinical development for the treatment of a rare pediatric epilepsy. The agreement also includes a research collaboration to discover and identify additional novel T-type calcium channel blockers as development candidates.

In connection with the exercise of the option, we paid Idorsia $45.0 million upfront, which we expensed as IPR&D in the second quarter of 2020. Further, as part of the research collaboration, we provided Idorsia with an incremental $7.2 million in funding, which we recorded as a prepaid asset and is being expensed over the two-year research collaboration term.

Pursuant to the terms of the agreement, upon the achievement of certain development and regulatory milestones, Idorsia may be entitled to receive additional payments of up to $365.0 million with respect to NBI-827104 and $620.0 million with respect to the development candidates. Idorsia may also be entitled to receive additional payments of up to $750.0 million upon the achievement of certain commercial milestones, as well as receive royalties on the future net sales of any collaboration product. Further, we will be responsible for all manufacturing, development and commercialization costs of any collaboration product.

Xenon Pharmaceuticals, Inc. In December 2019, we entered into a license and collaboration agreement with Xenon Pharmaceuticals Inc., or Xenon, to identify, research, and develop sodium channel inhibitors, including clinical candidate NBI-921352 (XEN901) and three preclinical candidates, which compounds we will have the exclusive right to further develop and commercialize under the terms and conditions set forth in the agreement.

We will be solely responsible, at our sole cost and expense, for all development and manufacturing of the compounds and any pharmaceutical product that contains a compound, subject to Xenon’s right to elect to co-fund the development of one product in a major indication and thus receive a mid-single digit percentage increase in royalties owed on the net sales of such product in the U.S. If Xenon exercises such option, the parties will share equally all reasonable and documented costs and expenses incurred in connection with the development of such product in the applicable indication, except costs and expenses that are solely related to the development of such product for regulatory approval outside the U.S.

In connection with the agreement, we paid Xenon $30.0 million upfront and purchased $20.0 million of Xenon’s common stock at $14.196 per share, representing approximately 1.4 million shares. Pursuant to the terms of the agreement, Xenon may also be entitled to receive additional payments of up to $1.7 billion upon the achievement of certain event-based milestones, as well as receive royalties on the future net sales of any collaboration product.

We accounted for the transaction as an asset acquisition as the set of acquired assets did not constitute a business. Our equity investment in Xenon was recorded at a fair value of $14.1 million after considering Xenon’s stock price on the date of closing and certain lock-up and voting provisions applicable to the acquired shares. The remaining $36.2 million of the purchase price, which includes the applicable transaction costs, was expensed as IPR&D in the fourth quarter of 2019.

Voyager Therapeutics, Inc. We entered into a collaboration and license agreement with Voyager Therapeutics, Inc., or Voyager, which became effective in March 2019, to develop and commercialize four programs using Voyager’s proprietary gene therapy platform. The four programs consist of the NBIb-1817 (VY-AADC) program for Parkinson’s disease, the Friedreich’s ataxia program and the rights to two undisclosed programs.

In connection with the agreement, we paid Voyager $115.0 million upfront and purchased $50.0 million of Voyager’s common stock at $11.9625 per share, representing approximately 4.2 million shares. Pursuant to the terms of the agreement, Voyager may also be entitled to receive additional payments of up to $1.7 billion upon the achievement of certain event-based milestones, as well as receive royalties on the future net sales of any collaboration product.

Pursuant to development plans agreed to by us and Voyager, unless Voyager exercises its co-development and co-commercialization rights as provided for in the agreement, we will be responsible for all development costs. Further, upon the occurrence of a specified event for each program, we will assume responsibility for the development, manufacturing, and commercialization activities of such program.

We accounted for the transaction as an asset acquisition as the set of acquired assets did not constitute a business. Our equity investment in Voyager was recorded at a fair value of $54.7 million after considering Voyager’s stock price on the date of closing and certain lock-up and voting provisions applicable to the acquired shares. The remaining $113.1 million of the purchase price, which includes the applicable transaction costs, was expensed as in-process research and development, or IPR&D, in the first quarter of 2019.

BIAL – Portela & Ca, S.A. We acquired the U.S. and Canada rights to ONGENTYS® from BIAL in the first quarter of 2017. We launched ONGENTYS in the U.S. in September 2020, after receiving FDA approval for ONGENTYS as an adjunctive therapy to levodopa/DOPA decarboxylase inhibitors in adult Parkinson's disease patients in April 2020. FDA approval for ONGENTYS for Parkinson’s disease resulted in a $20.0 million event-based payment to BIAL, which we expensed as R&D in the second quarter of 2020. We further recognized R&D expense of $10.0 million in each 2019 and 2018 in connection with BIAL’s achievement of certain regulatory event-based milestones related to then ongoing development of ONGENTYS. Pursuant to the terms of the agreement, BIAL may also be entitled to receive additional payments of up to $75.0 million upon the achievement of certain event-based milestones.

Under the terms of the agreement, we are responsible for the commercialization of ONGENTYS in the U.S. and Canada. Further, we rely on BIAL for the commercial supply of ONGENTYS. Upon our written request prior to the estimated expiration of the term of a licensed product, the parties shall negotiate a good faith continuation of BIAL’s supply of such licensed product after the term. After the term, and if BIAL is not supplying a certain licensed product, we shall pay BIAL a trademark royalty based on the net sales of such licensed product.

Since inception of the agreement, we have recognized revenue of $19.8 million associated with the delivery of a technology license and existing know-how and $15.0 million associated with the achievement of a certain event-based milestone. We further recognized revenue of $2.7 million in 2020 and $0.9 million in 2019 in connection with the ongoing KINECT-HD study, a placebo-controlled Phase III study of valbenazine in adult Huntington’s disease patients with chorea. In accordance with our continuing performance obligations, $6.7 million of the $30.0 million upfront payment received from MTPC is being deferred and will be recognized as revenue over the ongoing study period using an input method according to costs incurred to-date relative to estimated total costs associated with the study.

Pursuant to the terms of the agreement, we may also be entitled to receive additional payments of up to $70.0 million upon the achievement of certain event-based milestones, receive payments for the manufacture of certain pharmaceutical products, as well as receive royalties on the future net sales of any collaboration product in select territories in Asia.

Under the terms of the agreement, MTPC is responsible for all third-party development, marketing, and commercialization costs in Japan and other select Asian markets and we would be entitled to a percentage of sales of INGREZZA in Japan and other select Asian markets for the longer of ten years or the life of the related patent rights. Further, the collaboration effort between the parties to advance INGREZZA towards commercialization in Japan and other select Asian markets is governed by joint steering and development committees with representatives from both parties.

AbbVie received approval for ORILISSA for the management of moderate to severe endometriosis pain in women from the FDA in July 2018 and Health Canada in October 2018. In May 2020, AbbVie received FDA approval for ORIAHNN for the management of heavy menstrual bleeding associated with uterine fibroids in pre-menopausal women. We recognized sales-based royalties on AbbVie net sales of ORILISSA and ORIAHNN of $19.2 million in 2020, $14.3 million in 2019 and $1.6 million in 2018.

FDA approval for ORIAHNN for uterine fibroids resulted in the achievement of a $30.0 million event-based milestone, which we recognized as collaboration revenue in the second quarter of 2020. In 2019, we recognized collaboration revenue of $20.0 million in connection with the FDA’s acceptance of AbbVie’s NDA submission for the approval of ORIAHNN for uterine fibroids. In 2018, we recognized collaboration revenue of $40.0 million in connection with the FDA’s approval for ORILISSA for endometriosis.

Since inception of the agreement, we have recognized revenue of $75.0 million associated with the delivery of a technology license and existing know-how and $165.0 million associated with the achievement of certain event-based milestones. Pursuant to the terms of the agreement, we may also be entitled to receive additional payments of up to $366.0 million upon the achievement of certain event-based milestones.