Revenue Recognition - Estimated Revenue Expected to be Recognized in Future Related to Performance Obligations (Detail) $ in Thousands	3 Months Ended
Mar. 31, 2018 USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Transaction Price Allocated to the Remaining Performance Obligation as of March 31, 2018	$ 16,840
Bristol-Myers Squibb Company ("BMS") and Pfizer Inc. ("Pfizer") \| 2014 Agreement
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Transaction Price Allocated to the Remaining Performance Obligation as of March 31, 2018	$ 909
Expected Year By Which Revenue Recognition Will Be Completed	2019
Percentage of Revenue Recognized	94.00%
Bristol-Myers Squibb Company ("BMS") and Pfizer Inc. ("Pfizer") \| 2016 Agreement
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Transaction Price Allocated to the Remaining Performance Obligation as of March 31, 2018	$ 4,131
Expected Year By Which Revenue Recognition Will Be Completed	2021
Percentage of Revenue Recognized	73.00%
Daiichi Sankyo, Inc ("Daiichi") \| 2014 Agreement
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Transaction Price Allocated to the Remaining Performance Obligation as of March 31, 2018	$ 3,173
Expected Year By Which Revenue Recognition Will Be Completed	2019
Percentage of Revenue Recognized	91.00%
Daiichi Sankyo, Inc ("Daiichi") \| 2016 Agreement
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Transaction Price Allocated to the Remaining Performance Obligation as of March 31, 2018	$ 3,818
Expected Year By Which Revenue Recognition Will Be Completed	2021
Percentage of Revenue Recognized	69.00%
Bayer Pharma, AG ('Bayer") and Janssen Pharmaceuticals, Inc. ("Janssen") \| 2014 Agreement
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Transaction Price Allocated to the Remaining Performance Obligation as of March 31, 2018	$ 1,420
Expected Year By Which Revenue Recognition Will Be Completed	2019
Percentage of Revenue Recognized	94.00%
Bayer Pharma AG \| 2016 Agreement
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Transaction Price Allocated to the Remaining Performance Obligation as of March 31, 2018	$ 3,389
Expected Year By Which Revenue Recognition Will Be Completed	2021
Percentage of Revenue Recognized	73.00%

Percentage of revenue recognized.

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- Definition

Amount of transaction price allocated to performance obligation that has not been recognized as revenue.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 270
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=84173487&loc=SL51747714-108306

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=82913847&loc=SL49130556-203045

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+ References

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- Definition

Year in which remaining performance obligation is expected to be recognized, in CCYY format.

+ References

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