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.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130543-203045

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130539-203045

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130545-203045

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Collaboration Agreements - Other Collaborations (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended
	Feb. 28, 2018	Sep. 28, 2018	Sep. 29, 2017	Sep. 28, 2018	Sep. 29, 2017
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Royalty revenues on ex-U.S. sales		$ 225,397	$ 152,510	$ 625,224	$ 332,405
Collaboration Revenues
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Royalty revenues on ex-U.S. sales		$ 62,451	$ 56,094	$ 182,170	$ 79,108
Collaboration Revenues \| Collaborative arrangements with Daiichi Sankyo
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Royalty revenues on ex-U.S. sales	$ 20,000