License, Collaboration and Other Significant Agreements - Additional Information (Details)							1 Months Ended					3 Months Ended									12 Months Ended
		Feb. 14, 2020 USD ($)	Apr. 08, 2019 USD ($)	May 12, 2017 USD ($) $ / shares shares	Apr. 25, 2017 USD ($)	Feb. 09, 2017 USD ($) $ / shares shares	Jul. 31, 2019 USD ($)	Dec. 31, 2018 USD ($) shares	Mar. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2019 USD ($) shares	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($) shares	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2019 USD ($) Obligation shares	Dec. 31, 2018 USD ($) shares	Dec. 31, 2017 USD ($)	Sep. 30, 2017 USD ($)
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Recognized revenue under license agreement																					$ 335,001,000	$ 207,742,000	$ 181,227,000
Deferred revenue												$ 72,950,000									72,950,000
Collaborative arrangements additional cost sharing payments expected amount																					57,700,000
Deferred revenue, current								$ 56,980,000				39,830,000				$ 56,980,000					39,830,000	56,980,000
Deferred revenue, noncurrent								$ 55,709,000				$ 33,120,000				$ 55,709,000					$ 33,120,000	$ 55,709,000
Common stock shares sold | shares								116,887,518				121,674,568				116,887,518					121,674,568	116,887,518
License, Collaboration and Other Revenue
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Recognized revenue under license agreement												$ 40,640,000	$ 61,973,000	$ 71,714,000	$ 49,555,000	$ 53,026,000	$ 53,169,000	$ 48,793,000	$ 45,930,000		$ 223,882,000	$ 200,918,000	181,227,000
Accounts Receivable
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Accounts receivable	[1]							$ 1,587,000				15,822,000				1,587,000					15,822,000	1,587,000	34,186,000
Accounts Payable
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue								13,492,000								13,492,000						13,492,000
Mitsubishi Tanabe Pharma Corporation | License, Collaboration and Other Revenue
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Recognized revenue under license agreement																					$ 10,000,000	9,281,000	42,918,000
Mitsubishi Tanabe Pharma Corporation | Development and Commercialize Collaboration Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaboration Agreement, expiration period																					10 years
Collaboration Agreement, notice period for termination																					12 months
Upfront cash payment received											$ 20,000,000										$ 20,000,000
Percentage of royalty payments on sales																					20.00%
Additional milestone or royalty payments received																					$ 0
Number of performance obligations | Obligation																					2
Mitsubishi Tanabe Pharma Corporation | Development and Commercialize Collaboration Agreement | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone revenue											245,000,000
Mitsubishi Tanabe Pharma Corporation | New Agreement | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Data fee receivable																								$ 25,000,000
Mitsubishi Tanabe Pharma Corporation | Development And Commercialize Research And License Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront cash payment received																					$ 20,000,000
Cost of research services																					20,500,000
Deferred revenue												0									0
Accounts receivable												0									0
Mitsubishi Tanabe Pharma Corporation | Regulatory Milestone Payments
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone revenue							$ 10,000,000
Recognized revenue under license agreement																					10,000,000
Mitsubishi Tanabe Pharma Corporation | Regulatory Milestone Payments | Development and Commercialize Collaboration Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone revenue													10,000,000
Additional milestone revenue receivable												15,000,000									15,000,000
Mitsubishi Tanabe Pharma Corporation | Regulatory Milestone Payments | Development and Commercialize Collaboration Agreement | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront cash payment received																					40,000,000
Mitsubishi Tanabe Pharma Corporation | Regulatory Milestone Payments | Development And Commercialize Research And License Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone revenue																					10,000,000
Mitsubishi Tanabe Pharma Corporation | Development, Regulatory and Commercial Events | Development and Commercialize Collaboration Agreement | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone revenue																					225,000,000
Mitsubishi Tanabe Pharma Corporation | Development Milestones | Development and Commercialize Collaboration Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone revenue													$ 10,000,000								10,000,000
Mitsubishi Tanabe Pharma Corporation | Development Milestones | Development and Commercialize Collaboration Agreement | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront cash payment received																					40,000,000
Milestone revenue																					175,000,000
Mitsubishi Tanabe Pharma Corporation | Commercial Milestone Payments | Development and Commercialize Collaboration Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone revenue											$ 175,000,000
Mitsubishi Tanabe Pharma Corporation | Commercial Milestone Payments | Development and Commercialize Collaboration Agreement | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone revenue																					175,000,000
Mitsubishi Tanabe Pharma Corporation | Upfront | Development and Commercialize Collaboration Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Incurred clinical and commercial development cost																					20,500,000
Mitsubishi Tanabe Pharma Corporation | Development Milestones One | Development And Commercialize Research And License Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone revenue																					6,000,000
Mitsubishi Tanabe Pharma Corporation | Development Milestones Two | Development And Commercialize Research And License Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone revenue																					4,000,000
Mitsubishi Tanabe Pharma Corporation | Development and Commercialize Collaboration Agreement | Development And Commercialize Research And License Agreement | Accounts Receivable
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Accounts receivable												0									0
Otsuka Pharmaceutical Company. Ltd. | Development and Commercialize United States Collaboration and License Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone revenue																					$ 0
Number of performance obligations | Obligation																					3
Deferred revenue												44,171,000									$ 44,171,000
Collaborative arrangements cost sharing payments																					209,100,000
Collaborative arrangements additional cost sharing payments amount																					$ 43,700,000
Percentage of market penetration for license agreement																					90.00%
License agreement, notice period for termination																					12 months
Transaction price																					$ 425,600,000
Reimbursement for Otsuka's share of costs previously incurred																					$ 33,800,000
Transaction price, description																					As of December 31, 2019, the transaction price totaling $425.6 million is comprised of: (i) the up-front payment of $125.0 million, (ii) the cost share payment with respect to amounts incurred by the Company through December 31, 2016 of $33.8 million, (iii) the estimate of the cost base share payments to be received of approximately $209.1 million with respect to amounts incurred by the Company subsequent to December 31, 2016, and (iv) the estimate of the Additional Funding of approximately $57.7 million related to incremental cost share payments under the Otsuka Funding Option described above. As of December 31, 2019, no development or regulatory milestones have been assessed as probable of being reached and thus have been fully constrained.
Deferred revenue, current												23,530,000									$ 23,530,000
Deferred revenue, noncurrent												20,641,000									20,641,000
Cost share costs incurred																					1,800,000	1,200,000
Reimbursable by Otsuka																					700,000	500,000
Cost share costs by partner for license agreement																					1,900,000	1,100,000
Reimbursable to Otsuka																					1,000,000	500,000
Otsuka Pharmaceutical Company. Ltd. | Development and Commercialize United States Collaboration and License Agreement | Global Development Plan
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Reimbursement for Otsuka's share of costs previously incurred									$ 33,800,000
Collaborative arrangements additional cost sharing payments expected amount																					104,200,000
Otsuka Pharmaceutical Company. Ltd. | Development and Commercialize United States Collaboration and License Agreement | License, Collaboration and Other Revenue
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Recognized revenue under license agreement																					131,314,000	103,870,000	85,971,000
Otsuka Pharmaceutical Company. Ltd. | Development and Commercialize United States Collaboration and License Agreement | Accounts Receivable
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Accounts receivable												8,900,000									$ 8,900,000
Otsuka Pharmaceutical Company. Ltd. | Development and Commercialize United States Collaboration and License Agreement | Accounts Payable
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue, current								7,200,000								7,200,000						7,200,000
Otsuka Pharmaceutical Company. Ltd. | Development and Commercialize United States Collaboration and License Agreement | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Percentage of increase in funding to fund current global development costs																					80.00%
Otsuka Pharmaceutical Company. Ltd. | Development and Commercialize United States Collaboration and License Agreement | Minimum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Percentage of increase in funding to fund current global development costs																					52.50%
Reduction in percentage of future payments due upon current global development costs creditable																					50.00%
Percentage of remaining creditable amount applied to future payments																					50.00%
Otsuka Pharmaceutical Company. Ltd. | Development and Commercialize United States Collaboration and License Agreement | Minimum | Global Development Plan
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaborative arrangements cost sharing payments																					$ 266,800,000
Otsuka Pharmaceutical Company. Ltd. | Development and Commercialize International Collaboration and License Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Number of performance obligations | Obligation																					3
Deferred revenue												24,100,000									$ 24,100,000
Transaction price																					287,200,000
Reimbursement for Otsuka's share of costs previously incurred																					$ 200,000
Transaction price, description																					As of December 31, 2019, the transaction price totaling $287.2 million is comprised of: (i) the up-front payment of $73.0 million, (ii) the cost share payment with respect to amounts incurred by the Company during the quarter ended March 31, 2017 of $0.2 million, and (iii) an estimate of the cost share payments to be received with respect to amounts incurred by the Company subsequent to March 31, 2017 of $214.0 million. As of December 31, 2019, no development or regulatory milestones have been assessed as probable of being reached and thus have been fully constrained.
Deferred revenue, current												16,300,000									$ 16,300,000
Deferred revenue, noncurrent												7,800,000									7,800,000
Estimate Subsequent Cost Share Payment Receivable																					214,000,000
Milestone or royalty payments received					$ 0
Otsuka Pharmaceutical Company. Ltd. | Development and Commercialize International Collaboration and License Agreement | Global Development Plan
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Reimbursement for Otsuka's share of costs previously incurred																				$ 200,000
Otsuka Pharmaceutical Company. Ltd. | Development and Commercialize International Collaboration and License Agreement | License, Collaboration and Other Revenue
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Recognized revenue under license agreement																					75,614,000	87,320,000	$ 52,307,000
Otsuka Pharmaceutical Company. Ltd. | Development and Commercialize International Collaboration and License Agreement | Accounts Receivable
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Accounts receivable												$ 4,000,000									4,000,000
Otsuka Pharmaceutical Company. Ltd. | Development and Commercialize International Collaboration and License Agreement | Accounts Payable
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue, current								6,300,000								$ 6,300,000						6,300,000
Otsuka Pharmaceutical Company. Ltd. | Development and Commercialize International Collaboration and License Agreement | Minimum | Global Development Plan
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Estimate Subsequent Cost Share Payment Receivable					214,000,000
Otsuka Pharmaceutical Company. Ltd. | Regulatory Milestone Payments | Development and Commercialize United States Collaboration and License Agreement | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone revenue																					65,000,000
Otsuka Pharmaceutical Company. Ltd. | Regulatory Milestone Payments | Development and Commercialize International Collaboration and License Agreement | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone revenue					52,000,000
Otsuka Pharmaceutical Company. Ltd. | Development Milestones | Development and Commercialize United States Collaboration and License Agreement | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront cash payment received																					125,000,000
Otsuka Pharmaceutical Company. Ltd. | Development Milestones | Development and Commercialize International Collaboration and License Agreement | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront cash payment received					80,000,000
Otsuka Pharmaceutical Company. Ltd. | Commercial Milestone Payments | Development and Commercialize United States Collaboration and License Agreement | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone revenue																					575,000,000
Otsuka Pharmaceutical Company. Ltd. | Commercial Milestone Payments | Development and Commercialize International Collaboration and License Agreement | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone revenue					525,000,000
Otsuka Pharmaceutical Company. Ltd. | Up-front, Non-refundable and Non-creditable | Development and Commercialize United States Collaboration and License Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront cash payment received										$ 125,000,000											125,000,000
Otsuka Pharmaceutical Company. Ltd. | Up-front, Non-refundable and Non-creditable | Development and Commercialize International Collaboration and License Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront cash payment received					$ 73,000,000																73,000,000
Otsuka Pharmaceutical Company. Ltd. | Development and Regulatory Milestones | Development and Commercialize United States Collaboration and License Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone revenue																					0
Otsuka Pharmaceutical Company. Ltd. | Development and Regulatory Milestones | Development and Commercialize International Collaboration and License Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone revenue																					$ 0
Janssen Pharmaceutica NV | Development And Commercialize Research And License Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaboration Agreement, expiration period						10 years
Collaboration Agreement, notice period for termination						180 days
Milestone revenue						$ 215,000,000
Upfront cash payment received						16,500,000
Upfront payment made in cash						$ 1,000,000
Warrant to purchase common stock, shares | shares						509,611
Johnson & Johnson Innovation | Development And Commercialize Research And License Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Warrant to purchase common stock, shares | shares						509,611
Fair value of warrant									$ 3,400,000											$ 3,400,000
Exercise price | $ / shares						$ 9.81
Vifor (International) Ltd. | License Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone revenue			$ 25,000,000	$ 25,000,000
License agreement, notice period for termination																					12 months
Deferred revenue, noncurrent				$ 4,700,000
Common stock shares sold | shares				3,571,429
Sale of stock, price per share | $ / shares				$ 14.00
Proceeds from common stock sold				$ 50,000,000
Premium over the closing stock price of common stock | $ / shares				$ 12.69
Premium amount over the closing stock price of common stock				$ 4,700,000
Vifor (International) Ltd. | Priority Review Voucher Letter Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Payments after closing of PRV purchase		$ 10,000,000
Period of payments after closing of PRV purchase		15 days
Japan Tobacco Incorporation and Torii Pharmaceutical Company Limited | License, Collaboration and Other Revenue
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Recognized revenue under license agreement																					$ 5,882,000	$ 112,000
Japan Tobacco Incorporation and Torii Pharmaceutical Company Limited | License Agreement | Panion & BF Biotech, Incorporation
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Royalty payments								400,000													$ 10,200,000
Japan Tobacco Incorporation and Torii Pharmaceutical Company Limited | Sublicense Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Number of performance obligations | Obligation																					2
Recognized revenue under license agreement								$ 100,000													$ 5,900,000
License agreement, notice period for termination																					6 months
Potential payment for achievement of annual net sales milestones																					$ 55,000,000
Prior written notice for termination on the breach of agreement period																					60 days

[1] Excludes accounts receivable from other services related to clinical and regulatory activities performed by the Company on behalf of MTPC that are not included in the performance obligations identified under the MTPC Agreement as of December 31, 2019 and 2018. Also excludes accounts receivable related to amounts due to the Company from product sales which are included in the accompanying consolidated balance sheets as of December 31, 2019 and 2018.