Aggregate collaboration transaction amount.

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Common stock shares issuable under agreement.

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Future contingent milestone payment receivable.

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Contingent payments payable upon achieving development regulatory and commercial milestones.

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Estimated fair value of products.

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Estimated premium on issuance of shares.

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Lock-up period for share transaction under collaboration and license agreement.

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- Definition

Non-cash acquisition in-process research and development expense.

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- Definition

Number of additional collaboration target.

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- Definition

Number of targets.

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- Definition

Number of targets selected.

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- Definition

Period used to calculate weighted average price per share.

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- Definition

Premium on issuance of shares allocated to equity.

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- Definition

Profit share upon exercise of co-development option.

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- Definition

Royalty payment percentage equivalence to sublicense proceeds.

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- Definition

Successful product development percentage.

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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.

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No definition available.

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- Definition

Face amount or stated value per share of common stock.

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Amount of deferred revenue as of balance sheet date. Deferred revenue represents collections of cash or other assets related to a revenue producing activity for which revenue has not yet been recognized. Generally, an entity records deferred revenue when it receives consideration from a customer before achieving certain criteria that must be met for revenue to be recognized in conformity with GAAP.

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- Definition

For an unclassified balance sheet, amount of receivables due from an entity that is affiliated with the reporting entity by means of direct or indirect ownership.

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Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Total obligations incurred as part of normal operations that are expected to be paid during the following twelve months or within one business cycle, if longer.

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Cash received from collaborators during the current period.

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The cash inflow from the additional capital contribution to the entity.

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Rate applied to the undiscounted amount of estimated damages for product liability to arrive at the present value recorded as of the balance sheet date.

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The amount of consideration recognized during the period for the milestone or milestones.

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Price of a single share of a number of saleable stocks of a company.

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Research and Collaboration Agreements - Amgen, Inc - Additional Information (Details)		1 Months Ended	12 Months Ended
	Sep. 29, 2017 USD ($) Target	Oct. 31, 2017 USD ($) $ / shares shares	Dec. 31, 2017 USD ($) $ / shares	Dec. 31, 2016 USD ($) $ / shares	Oct. 14, 2015 $ / shares
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Common stock, par value \| $ / shares			$ 0.00001	$ 0.00001	$ 0.00001
Common stock, value of shares issued in connection with agreement			$ 19,957,000
Liabilities Current			61,147,000	$ 35,767,000
Probability for successful product development, percentage	11.00%
Product Liability Contingency, Accrual, Discount Rate	9.00%
Patents
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Finite-Lived Intangible Asset, Useful Life	12 years
Collaboration and License Agreement \| Amgen Inc
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Common stock, shares issuable under agreement \| shares		1,156,069
Common stock, shares issuable under agreement, price per share \| $ / shares		$ 17.30
Common stock, par value \| $ / shares		$ 0.00001
Common stock, value of shares issued in connection with agreement		$ 20,000
Period used to calculate weighted average price per share		20 days
Lock-up period for share disposal		6 months
Estimated premium on the stock sold		$ 500,000
Number of targets \| Target	3
Number of targets selected \| Target	1
Number of additional collaboration target \| Target	2
Total transaction price	$ 51,200,000
Portion of transaction price allocated to premium on sale of equity	500,000
Estimated fair value of products	10,700,000
Non-cash acquisition of in-process research and development expense			10,700,000
Revenue recognized from collaborative arrangement			1,300,000
Amount due from agreement			0
Collaboration and License Agreement \| Amgen Inc \| EGFR Products
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue			45,300,000
Collaboration and License Agreement \| Amgen Inc \| Amgen Other Products
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue			$ 4,600,000
Collaboration and License Agreement \| Amgen Inc \| Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Contingent milestone payments receivable	950,000,000
Contingent payments payable	203,000,000
Collaboration and License Agreement \| Amgen Inc \| Maximum \| EGFR Products
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Contingent milestone payments receivable	$ 455,000,000
Percentage share of profit and losses	50.00%
Collaboration and License Agreement \| Amgen Inc \| Up Front Payment Arrangement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront payment received		$ 40,000
Sublicense Agreement \| Amgen Inc \| UC Regents
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Royalty payment percentage	15.00%
Liabilities Current	$ 2,100,000