COMMITMENTS AND CONTINGENCIES (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2020	Sep. 30, 2020
Ionis Pharmaceuticals, Inc.
Commitments And Contingencies [Line Items]
Increase in contingent liability accrual	$ 28	$ 28

Amount of increase (decrease) in loss contingency liability.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=118942415&loc=d3e14326-108349

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Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration