Subsequent Event	12 Months Ended
Dec. 31, 2020
Subsequent Events [Abstract]
Subsequent Event	Note 16: Subsequent Event In February 2021, Gilead increased its ownership in the Company by purchasing 5,650,000 additional shares of the Company’s common stock at a purchase price of $39.00 per share for total proceeds to the Company of $220.4 million. After the transaction, Gilead owned approximately $19.5% of the Company’s outstanding shares of common stock.

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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