DEBT AND CREDIT FACILITIES - Summary of Debt Carrying Amount (Details) - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023
Debt Instrument [Line Items]
Total debt, net	$ 23,349	$ 24,987
Less: Current portion of long-term debt and other obligations, net	1,809	1,798
Total Long-term debt, net	21,540	23,189
Senior Notes and Medium-Term Notes
Debt Instrument [Line Items]
Total senior unsecured notes	22,091	23,834
Liability related to future royalties
Debt Instrument [Line Items]
Total debt, net	1,159	1,153
Liability related to assumed financing arrangement | CymaBay
Debt Instrument [Line Items]
Total debt, net	$ 99	0
3.70% Senior Unsecured Notes Due April 2024 | Senior Notes
Debt Instrument [Line Items]
Interest Rate	3.70%
Total debt, net	$ 0	1,750
3.50% Senior Unsecured Notes Due February 2025 | Senior Notes
Debt Instrument [Line Items]
Interest Rate	3.50%
Total debt, net	$ 1,749	1,749
3.65% Senior Unsecured Notes Due March 2026 | Senior Notes
Debt Instrument [Line Items]
Interest Rate	3.65%
Total debt, net	$ 2,746	2,744
2.95% Senior Unsecured Notes Due March 2027 | Senior Notes
Debt Instrument [Line Items]
Interest Rate	2.95%
Total debt, net	$ 1,248	1,248
1.20% Senior Unsecured Notes Due October 2027 | Senior Notes
Debt Instrument [Line Items]
Interest Rate	1.20%
Total debt, net	$ 748	747
1.65% Senior Unsecured Notes Due October 2030 | Senior Notes
Debt Instrument [Line Items]
Interest Rate	1.65%
Total debt, net	$ 995	994
5.25% Senior Unsecured Notes Due October 2033 | Senior Notes
Debt Instrument [Line Items]
Interest Rate	5.25%
Total debt, net	$ 993	992
4.60% Senior Unsecured Notes Due September 2035 | Senior Notes
Debt Instrument [Line Items]
Interest Rate	4.60%
Total debt, net	$ 993	993
4.00% Senior Unsecured Notes Due September 2036 | Senior Notes
Debt Instrument [Line Items]
Interest Rate	4.00%
Total debt, net	$ 743	743
2.60% Senior Unsecured Notes Due October 2040 | Senior Notes
Debt Instrument [Line Items]
Interest Rate	2.60%
Total debt, net	$ 989	988
5.65% Senior Unsecured Notes Due December 2041 | Senior Notes
Debt Instrument [Line Items]
Interest Rate	5.65%
Total debt, net	$ 996	996
4.80% Senior Unsecured Notes Due April 2044 | Senior Notes
Debt Instrument [Line Items]
Interest Rate	4.80%
Total debt, net	$ 1,737	1,737
4.50% Senior Unsecured Notes Due February 2045 | Senior Notes
Debt Instrument [Line Items]
Interest Rate	4.50%
Total debt, net	$ 1,735	1,734
4.75% Senior Unsecured Notes Due March 2046 | Senior Notes
Debt Instrument [Line Items]
Interest Rate	4.75%
Total debt, net	$ 2,223	2,222
4.15% Senior Unsecured Notes Due March 2047 | Senior Notes
Debt Instrument [Line Items]
Interest Rate	4.15%
Total debt, net	$ 1,729	1,729
2.80% Senior Unsecured Notes Due October 2050 | Senior Notes
Debt Instrument [Line Items]
Interest Rate	2.80%
Total debt, net	$ 1,478	1,478
5.55% Senior Unsecured Notes Due October 2053 | Senior Notes
Debt Instrument [Line Items]
Interest Rate	5.55%
Total debt, net	$ 988	$ 988