FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS - Additional Information (Details) € in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2021 USD ($) facility	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Jan. 31, 2022 USD ($)	Dec. 31, 2021 EUR (€) facility
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Recognized in Other Comprehensive Income/(Loss)	$ 364	$ (216)	$ 65
Principal Value	$ 43,095	48,711
Variable rate debt, lower range of basis point spread	4.60%				4.60%
Long-term debt, fair value	$ 49,100	58,500
Line of credit facility, maximum borrowing capacity	6,000
Extinguishment of debt	3,500
Payment for debt extinguishment	4,000
Loss on debt redemption	281	0	0
Repayments of notes payable	2,000	2,800	1,300
Interest payments	1,500	1,600	414
Long-term debt, maturity, year one	6,100
Long-term debt, maturity, year two	5,100
Long-term debt, maturity, year three	4,100
Long-term debt, maturity, year four	4,700
Long-term debt, maturity, year five	$ 3,500
Number of revolving credit facilities | facility	4				4
Securities borrowed, fair value of collateral	$ 1,200
$2 Billion Maximum Borrowing Capacity
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Line of credit facility, maximum borrowing capacity	2,000
$1 Billion Maximum Borrowing Capacity
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Line of credit facility, maximum borrowing capacity	1,000
$1.5 Billion Maximum Borrowing Capacity
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Line of credit facility, maximum borrowing capacity	$ 1,500
Long-term debt, term (in years)	5 years				5 years
Term Loan Credit Agreement
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Line of credit facility, maximum borrowing capacity			8,000
Term Loan Credit Agreement | 364-Day Tranche
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Line of credit facility, maximum borrowing capacity			1,000
Term Loan Credit Agreement | Three-Year Tranche
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Line of credit facility, maximum borrowing capacity			4,000
Term Loan Credit Agreement | Five-Year Tranche
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Line of credit facility, maximum borrowing capacity			3,000
$5 Billion Maximum Borrowing Capacity | Subsequent Event
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Line of credit facility, maximum borrowing capacity				$ 5,000
Long-term debt, term (in years)				5 years
Renewal period				1 year
$7.0 Billion Fixed Rate Unsecured Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Principal Value		7,000
Proceeds from debt, net of issuance costs		6,900
$19 Billion Senior Unsecured Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Principal Value			19,000
Proceeds from debt, net of issuance costs			18,800
Senior Notes Debt Exchange
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Principal Value			18,500
Senior Notes Debt Exchange | Celgene
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Principal Value			19,900
Senior Notes Debt Exchange Remaining Principal Amount | Celgene
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Principal Value			1,300
London Interbank Offered Rate (LIBOR)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
LIBOR	0.10%				0.10%
Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Principal Value	$ 1,100				€ 950
Foreign currency forward contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Recognized in Other Comprehensive Income/(Loss)	364	(267)	65
Treasury Lock
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Recognized in Other Comprehensive Income/(Loss)	0	51	$ 0
Treasury Lock | Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative, notional amount		$ 2,100
Euro Member Countries, Euro | Foreign currency forward contracts | Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative, notional amount	3,500
Japan, Yen | Foreign currency forward contracts | Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative, notional amount	1,200
Japan, Yen | Cross-currency interest rate swap contracts | Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative, notional amount	$ 600