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AVAILABLE-FOR-SALE DEBT SECURITIES AND EQUITY SECURITIES - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Available-for-Sale Securities
Allowance for credit losses	$ 0
Selling, general and administrative expenses	6,090	$ 5,673	$ 5,246
Galapagos \| Fair value, recurring
Available-for-Sale Securities
Marketable equity securities	686
Equity investment, noncurrent		736
Galapagos \| Level 1 \| Fair value, recurring
Available-for-Sale Securities
Marketable equity securities	686
Arcus \| Fair value, recurring
Available-for-Sale Securities
Marketable equity securities	$ 283	286
Gilead Foundation \| Related Party
Available-for-Sale Securities
Selling, general and administrative expenses		$ 85	$ 212