DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES - Fair Value of Derivative Instruments in the Condensed Consolidated Statements of Financial Position (Details) - USD ($) $ in Millions	Jul. 31, 2020	Jan. 31, 2020
Derivatives, Fair Value [Line Items]
Asset position	$ 594	$ 299
Liability position	(575)	(286)
Gross Amounts of Recognized Assets/ (Liabilities)	19	13
Other Current Assets
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets/ (Liabilities)	327	80
Other Non- Current Assets
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets/ (Liabilities)	11	1
Other Current Liabilities
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets/ (Liabilities)	(271)	(30)
Other Non-Current Liabilities
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets/ (Liabilities)	(48)	(38)
Designated as cash flow hedging instruments
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets/ (Liabilities)	(83)	118
Designated as cash flow hedging instruments | Other Current Assets
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets/ (Liabilities)	(22)	106
Designated as cash flow hedging instruments | Other Non- Current Assets
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets/ (Liabilities)	0	0
Designated as cash flow hedging instruments | Other Current Liabilities
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets/ (Liabilities)	(61)	12
Designated as cash flow hedging instruments | Other Non-Current Liabilities
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets/ (Liabilities)	0	0
Designated as cash flow hedging instruments | Foreign exchange contracts
Derivatives, Fair Value [Line Items]
Asset position	31	123
Liability position	(114)	(5)
Designated as cash flow hedging instruments | Foreign exchange contracts | Other Current Assets
Derivatives, Fair Value [Line Items]
Asset position	15	108
Liability position	(37)	(2)
Designated as cash flow hedging instruments | Foreign exchange contracts | Other Non- Current Assets
Derivatives, Fair Value [Line Items]
Asset position	0	0
Liability position	0	0
Designated as cash flow hedging instruments | Foreign exchange contracts | Other Current Liabilities
Derivatives, Fair Value [Line Items]
Asset position	16	15
Liability position	(77)	(3)
Designated as cash flow hedging instruments | Foreign exchange contracts | Other Non-Current Liabilities
Derivatives, Fair Value [Line Items]
Asset position	0	0
Liability position	0	0
Non-designated as hedging instruments
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets/ (Liabilities)	102	(105)
Non-designated as hedging instruments | Other Current Assets
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets/ (Liabilities)	349	(26)
Non-designated as hedging instruments | Other Non- Current Assets
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets/ (Liabilities)	11	1
Non-designated as hedging instruments | Other Current Liabilities
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets/ (Liabilities)	(210)	(42)
Non-designated as hedging instruments | Other Non-Current Liabilities
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets/ (Liabilities)	(48)	(38)
Non-designated as hedging instruments | Foreign exchange contracts
Derivatives, Fair Value [Line Items]
Asset position	553	175
Liability position	(417)	(249)
Non-designated as hedging instruments | Foreign exchange contracts | Other Current Assets
Derivatives, Fair Value [Line Items]
Asset position	472	136
Liability position	(123)	(162)
Non-designated as hedging instruments | Foreign exchange contracts | Other Non- Current Assets
Derivatives, Fair Value [Line Items]
Asset position	1	0
Liability position	0	0
Non-designated as hedging instruments | Foreign exchange contracts | Other Current Liabilities
Derivatives, Fair Value [Line Items]
Asset position	80	39
Liability position	(290)	(81)
Non-designated as hedging instruments | Foreign exchange contracts | Other Non-Current Liabilities
Derivatives, Fair Value [Line Items]
Asset position	0	0
Liability position	(4)	(6)
Non-designated as hedging instruments | Interest rate contracts
Derivatives, Fair Value [Line Items]
Asset position	10	1
Liability position	(44)	(32)
Non-designated as hedging instruments | Interest rate contracts | Other Current Assets
Derivatives, Fair Value [Line Items]
Asset position	0	0
Liability position	0	0
Non-designated as hedging instruments | Interest rate contracts | Other Non- Current Assets
Derivatives, Fair Value [Line Items]
Asset position	10	1
Liability position	0	0
Non-designated as hedging instruments | Interest rate contracts | Other Current Liabilities
Derivatives, Fair Value [Line Items]
Asset position	0	0
Liability position	0	0
Non-designated as hedging instruments | Interest rate contracts | Other Non-Current Liabilities
Derivatives, Fair Value [Line Items]
Asset position	0	0
Liability position	$ (44)	$ (32)