DEBT AND CREDIT FACILITIES - Summary of Debt Carrying Amount (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Debt Instrument [Line Items]
Total debt, net	$ 25,193	$ 24,987
Less: Current portion of long-term debt and other obligations, net	3,667	1,798
Total Long-term debt, net	$ 21,527	23,189
Senior Notes | 3.70% Senior Unsecured Notes Due April 2024
Debt Instrument [Line Items]
Interest Rate	3.70%
Total debt, net	$ 1,750	1,750
Senior Notes | 3.50% Senior Unsecured Notes Due February 2025
Debt Instrument [Line Items]
Interest Rate	3.50%
Total debt, net	$ 1,749	1,749
Senior Notes | 3.65% Senior Unsecured Notes Due March 2026
Debt Instrument [Line Items]
Interest Rate	3.65%
Total debt, net	$ 2,745	2,744
Senior Notes | 2.95% Senior Unsecured Notes Due March 2027
Debt Instrument [Line Items]
Interest Rate	2.95%
Total debt, net	$ 1,248	1,248
Senior Notes | 1.20% Senior Unsecured Notes Due October 2027
Debt Instrument [Line Items]
Interest Rate	1.20%
Total debt, net	$ 748	747
Senior Notes | 1.65% Senior Unsecured Notes Due October 2030
Debt Instrument [Line Items]
Interest Rate	1.65%
Total debt, net	$ 995	994
Senior Notes | 5.25% Senior Unsecured Notes Due October 2033
Debt Instrument [Line Items]
Interest Rate	5.25%
Total debt, net	$ 992	992
Senior Notes | 4.60% Senior Unsecured Notes Due September 2035
Debt Instrument [Line Items]
Interest Rate	4.60%
Total debt, net	$ 993	993
Senior Notes | 4.00% Senior Unsecured Notes Due September 2036
Debt Instrument [Line Items]
Interest Rate	4.00%
Total debt, net	$ 743	743
Senior Notes | 2.60% Senior Unsecured Notes Due October 2040
Debt Instrument [Line Items]
Interest Rate	2.60%
Total debt, net	$ 988	988
Senior Notes | 5.65% Senior Unsecured Notes Due December 2041
Debt Instrument [Line Items]
Interest Rate	5.65%
Total debt, net	$ 996	996
Senior Notes | 4.80% Senior Unsecured Notes Due April 2044
Debt Instrument [Line Items]
Interest Rate	4.80%
Total debt, net	$ 1,737	1,737
Senior Notes | 4.50% Senior Unsecured Notes Due February 2045
Debt Instrument [Line Items]
Interest Rate	4.50%
Total debt, net	$ 1,734	1,734
Senior Notes | 4.75% Senior Unsecured Notes Due March 2046
Debt Instrument [Line Items]
Interest Rate	4.75%
Total debt, net	$ 2,223	2,222
Senior Notes | 4.15% Senior Unsecured Notes Due March 2047
Debt Instrument [Line Items]
Interest Rate	4.15%
Total debt, net	$ 1,729	1,729
Senior Notes | 2.80% Senior Unsecured Notes Due October 2050
Debt Instrument [Line Items]
Interest Rate	2.80%
Total debt, net	$ 1,478	1,478
Senior Notes | 5.55% Senior Unsecured Notes Due October 2053
Debt Instrument [Line Items]
Interest Rate	5.55%
Total debt, net	$ 988	988
Senior Notes and Medium-Term Notes
Debt Instrument [Line Items]
Total senior unsecured notes	23,838	23,834
Liability related to future royalties
Debt Instrument [Line Items]
Total debt, net	1,157	1,153
Liability related to assumed financing arrangement | CymaBay
Debt Instrument [Line Items]
Total debt, net	$ 199	$ 0