Subsequent Event	6 Months Ended
Jun. 30, 2022
Subsequent Events [Abstract]
Subsequent Event	11. Subsequent Event On August 3, 2022, the Company entered into an Agreement and Plan of Merger with Amgen Inc. (Amgen) under which Amgen will acquire the Company for $52.00 per share in cash, representing an enterprise value of approximately $3.7 billion. The transaction is subject to the Company's stockholder approval, regulatory approvals and other customary closing conditions, and is expected to close in the fourth quarter of 2022.

The entire disclosure for significant events or transactions that occurred after the balance sheet date through the date the financial statements were issued or the date the financial statements were available to be issued. Examples include: the sale of a capital stock issue, purchase of a business, settlement of litigation, catastrophic loss, significant foreign exchange rate changes, loans to insiders or affiliates, and transactions not in the ordinary course of business.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 855
-URI http://asc.fasb.org/topic&trid=2122774

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 855
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6842918&loc=SL6314017-165662

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