COMMITMENTS AND CONTINGENCIES (Details)	1 Months Ended			6 Months Ended	12 Months Ended
	Apr. 30, 2020 plaintiff agreement	Dec. 31, 2019 USD ($) opposingParty patent	Aug. 31, 2017 plaintiff	Jun. 30, 2021 USD ($) lawsuit plaintiff	Dec. 31, 2016 party
Loss Contingencies [Line Items]
Number of patents challenged, scenario one | patent		4
Number of patents challenged, scenario two | patent		2
Juno Therapeutics, Inc. and Sloan Kettering Cancer Center
Loss Contingencies [Line Items]
Damages awarded		$ 585,000,000
Running royalty rate from October 2017		27.60%
Enhancement rate on past damages	50.00%
Running royalty rate on future sales	27.60%
Estimate of possible loss representing past sales				$ 811,000,000
Estimate of possible loss representing enhancement of past damages				389,000,000
Estimate of possible loss representing royalties and prejudgment interest				285,000,000
Juno Therapeutics, Inc. and Sloan Kettering Cancer Center | Minimum
Loss Contingencies [Line Items]
Estimate of possible loss				0
Juno Therapeutics, Inc. and Sloan Kettering Cancer Center | Maximum
Loss Contingencies [Line Items]
Estimate of possible loss				1,500,000,000
ViiV Healthcare Company | Pending Litigation
Loss Contingencies [Line Items]
Damages amount				$ 14,500,000,000
Pre-Exposure Prophylaxis
Loss Contingencies [Line Items]
Number of material transfer agreements | agreement	4
European Patent Claims 2024 Expiration
Loss Contingencies [Line Items]
Number of parties appealed | opposingParty		2
European Patent Claims 2026 Expiration
Loss Contingencies [Line Items]
Number of parties appealed | opposingParty		3
European Patent Claims 2032 Expiration
Loss Contingencies [Line Items]
Number of parties appealed | opposingParty		3
European Patent Claims 2027 Expiration
Loss Contingencies [Line Items]
Number of parties appealed | opposingParty		2
Number of parties filing opposition | party					3
Product Liability
Loss Contingencies [Line Items]
Number of class action lawsuits | lawsuit				2
Number of plaintiffs involved | plaintiff				23,000
Qui Tam
Loss Contingencies [Line Items]
Number of plaintiffs involved | plaintiff	2		2