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Collaboration Agreements - Product Revenue - Additional Information 5 (Detail) - Astellas Agreement [Member] - Japan [Member] - USD ($) $ in Millions | 1 Months Ended | 3 Months Ended | 12 Months Ended
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Dec. 31, 2018 | Jun. 30, 2018 | Dec. 31, 2018
Revenue Recognition, Multiple-deliverable Arrangements [Line Items] |  |  |
Contract with customer liability, revenue recognized | $ 43.9 | $ 20.9 |
Product Revenue [Member] |  |  |
Revenue Recognition, Multiple-deliverable Arrangements [Line Items] |  |  |
Contract with customer liability, revenue recognized |  |  | $ 64.8

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- Definition 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. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 50 -Paragraph 8 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130549-203045 + Details
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
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- Details
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- Details
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- Details
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