The amount of additional consideration based on net sales of product as defined under a collaboration agreement.

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Represents the potential amount of milestone payments related to development and regulatory approval under the collaborative agreement.

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Represents the total potential amount of milestone payments related to development, regulatory approval and commercial sales under the collaborative agreement.

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Represents the amount of fixed and determinable non-contingent upfront payments included under the collaborative agreement as arrangement consideration.

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Transaction price allocated to performance obligations.

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Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable, classified as current.

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Amount of revenue recognized that was previously included in balance of obligation to transfer good or service to customer for which consideration from customer has been received or is due.

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The aggregate costs incurred in the production of goods for sale.

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Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

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Amount of revenue, fees and commissions earned from transactions between (a) a parent company and its subsidiaries; (b) subsidiaries of a common parent; (c) an entity and trusts for the benefit of employees, for example, but not limited to, pension and profit-sharing trusts that are managed by or under the trusteeship of the entity's management; (d) an entity and its principal, owners, management, or members of their immediate families; and (e) affiliates.

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Amount of consideration paid in advance for supplies that provide economic benefits within a future period of one year or the normal operating cycle, if longer.

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Collaboration Agreements, License Agreement and Revenues - Astellas Agreements - Additional Information (Detail) - USD ($)	1 Months Ended				3 Months Ended		12 Months Ended			35 Months Ended	45 Months Ended
	Dec. 31, 2020	Sep. 30, 2019	Apr. 30, 2006	Jun. 30, 2005	Sep. 30, 2021	Jun. 30, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Feb. 28, 2009	Feb. 28, 2009	Jun. 30, 2019
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total revenue							$ 235,309,000	$ 176,319,000	$ 256,577,000
Unbilled contract asset	$ 2,147,000						66,909,000	2,147,000
Deferred Revenue	6,547,000						15,857,000	6,547,000
Drug Product Revenue [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total revenue							$ 962,000	8,906,000	(36,324,000)
Japan [Member] \| Drug Product Revenue [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total revenue						$ 8,200,000
Astellas Agreement [Member] \| Japan [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Upfront, non-contingent and time-based payments received											$ 40,100,000
Potential milestone payments	15,000,000.0	$ 12,500,000		$ 132,500,000
Commercial sales milestone				15,000,000.0
Additional consideration based on net sales description							the low 20% range of the list price
Transaction price and allocated to performance obligations	$ 15,000,000.0	$ 12,500,000						15,000,000.0
Aggregate considerations received excluding drug product revenue							$ 105,100,000
Astellas Agreement [Member] \| Japan [Member] \| Drug Product Revenue [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total revenue							$ 2,100,000	$ 4,300,000	(36,300,000)
Astellas Agreement [Member] \| Japan [Member] \| Clinical and Development Milestone [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Potential milestone payments				22,500,000
Astellas Agreement [Member] \| Japan [Member] \| Regulatory Milestone [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Potential milestone payments				$ 95,000,000.0
Astellas Agreement [Member] \| Europe [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Upfront, non-contingent and time-based payments received										$ 320,000,000.0
Potential milestone payments					$ 120,000.0
Additional consideration based on net sales description							low 20% range
Transaction price and allocated to performance obligations					$ 120,000.0							$ 130,000,000.0
Aggregate considerations received excluding drug product revenue							$ 660,000,000.0
Development and regulatory approval milestones			$ 425,000,000.0
Percentage of joint development costs committed to fund			50.00%
Revenue related to collaboration agreements									128,800,000
Unbilled contract asset									$ 130,000,000.0
Milestone payment received						$ 130,000,000.0
Astellas Agreement [Member] \| Europe [Member] \| Drug Product Revenue [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Burdened manufacturing costs							1,000,000.0
Deferred Revenue							$ 25,900,000
Astellas Agreement [Member] \| Europe [Member] \| Clinical and Development Milestone [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Potential milestone payments			$ 90,000,000.0
Astellas Agreement [Member] \| Europe [Member] \| Regulatory Milestone [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Potential milestone payments			$ 335,000,000.0