Represents the maximum contractual maturity period for available-for-sale securities.

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- Definition

Number of regulatory milestones.

+ References

No definition available.

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- Definition

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

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- Definition

Amount of valuation reserve for inventory.

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- Definition

The amount by which the fair value of an investment in debt and equity securities categorized as Available-for-sale is less than the amortized cost basis or carrying amount of that investment at the balance sheet date and the decline in fair value is deemed to be other than temporary, before considering whether or not such amount is recognized in earnings or other comprehensive income.

+ References

No definition available.

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- Definition

Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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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.

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- Definition

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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Balance Sheet Components - Additional Information (Detail)	3 Months Ended		6 Months Ended
	Jun. 30, 2019 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2019 USD ($) Milestone	Jun. 30, 2018 USD ($)	Dec. 31, 2018 USD ($)
Schedule of Available-for-sale Securities [Line Items]
Cash and cash equivalents	$ 74,587,000		$ 74,587,000		$ 89,258,000
Contractual maturities of available-for-sale investments			1 year
Other-than-temporary impairment loss	0	$ 0	$ 0	$ 0
Provision to write-down excess and obsolete inventory	0		$ 0
Number of regulatory milestones \| Milestone			2
Unbilled contract assets	180,000,000		$ 180,000,000		0
Building shell cost	140,786,000		140,786,000		192,397,000
Accumulated depreciation	95,921,000		95,921,000		65,199,000
Building shell [Member]
Schedule of Available-for-sale Securities [Line Items]
Building shell cost	0		0		53,880,000
Building [Member] \| Build to suit arrangements [Member]
Schedule of Available-for-sale Securities [Line Items]
Accumulated depreciation					13,500,000
Leasehold improvements [Member]
Schedule of Available-for-sale Securities [Line Items]
Building shell cost	101,250,000		101,250,000		101,200,000
Leasehold improvements [Member] \| Accounting standards update 2016-02 [Member]
Schedule of Available-for-sale Securities [Line Items]
Accumulated depreciation	38,900,000		38,900,000
Europe [Member]
Schedule of Available-for-sale Securities [Line Items]
Unbilled contract assets	130,000,000.0		130,000,000.0
Astellas Agreement [Member] \| Europe [Member]
Schedule of Available-for-sale Securities [Line Items]
Unbilled contract assets	130,000,000.0		130,000,000.0
AstraZeneca Agreements [Member]
Schedule of Available-for-sale Securities [Line Items]
Unbilled contract assets	50,000,000.0		50,000,000.0
AstraZeneca Agreements [Member] \| U.S./RoW [Member]
Schedule of Available-for-sale Securities [Line Items]
Unbilled contract assets	50,000,000.0		50,000,000.0
Foreign subsidiaries [Member]
Schedule of Available-for-sale Securities [Line Items]
Cash and cash equivalents	$ 26,000,000.0		$ 26,000,000.0		$ 21,900,000