Amount of short-term debt and current maturity of long-term debt and capital lease obligations due within one year or the normal operating cycle, if longer.

Name:	us-gaap_DebtCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=120520924&loc=SL6031897-161870

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

+ Details

Name:	us-gaap_DebtInstrumentCarryingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount, after accumulated amortization, of debt discount (premium).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=119993939&loc=d3e28555-108399

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=119993939&loc=d3e28551-108399

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=119993939&loc=d3e28567-108399

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=119993939&loc=d3e28541-108399

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

+ Details

Name:	us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.17)
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=119993939&loc=d3e28555-108399

+ Details

Name:	us-gaap_DeferredFinanceCostsNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The effective interest rate at the end of the reporting period.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)(3)
-URI http://asc.fasb.org/extlink&oid=120520924&loc=SL6031897-161870

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16))
-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

Name:	us-gaap_LongTermDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount after unamortized (discount) premium and debt issuance costs of long-term debt classified as noncurrent and excluding amounts to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

+ Details

Name:	us-gaap_LongTermDebtNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

DEBT - Outstanding Debt (Details) - USD ($) $ in Millions	Jul. 31, 2020	Jan. 31, 2020	Sep. 07, 2016
Debt Instrument [Line Items]
Total debt, principal amount	$ 54,537	$ 52,665
Unamortized discount, net of unamortized premium	(226)	(241)
Debt issuance costs	(358)	(368)
Total debt, carrying value	53,953	52,056
Total short-term debt, carrying value	10,345	7,737
Total long-term debt, carrying value	43,608	44,319
DFS Debt
Debt Instrument [Line Items]
Total debt, principal amount	8,837
2.51% Margin Loan Facility due April 2022
Debt Instrument [Line Items]
Total debt, principal amount	4,000
Secured Debt \| 2.75% Term Loan B-1 Facility due September 2025
Debt Instrument [Line Items]
Total debt, principal amount	$ 4,691	4,738
Interest rate at period end	2.75%
Secured Debt \| 1.93% Term Loan A-4 Facility due December 2023
Debt Instrument [Line Items]
Total debt, principal amount	$ 679	679
Interest rate at period end	1.93%
Secured Debt \| 1.93% Term Loan A-6 Facility due March 2024
Debt Instrument [Line Items]
Total debt, principal amount	$ 3,316	3,497
Interest rate at period end	1.93%
Secured Debt \| 4.42% due June 2021
Debt Instrument [Line Items]
Total debt, principal amount	$ 3,065	4,500
Interest rate	4.42%
Secured Debt \| 5.45% due June 2023
Debt Instrument [Line Items]
Total debt, principal amount	$ 3,750	3,750
Interest rate	5.45%
Secured Debt \| 4.00% due July 2024
Debt Instrument [Line Items]
Total debt, principal amount	$ 1,000	1,000
Interest rate	4.00%
Secured Debt \| 5.85% due July 2025
Debt Instrument [Line Items]
Total debt, principal amount	$ 1,000	0
Interest rate	5.85%
Secured Debt \| 6.02% due June 2026
Debt Instrument [Line Items]
Total debt, principal amount	$ 4,500	4,500
Interest rate	6.02%
Secured Debt \| 4.90% due October 2026
Debt Instrument [Line Items]
Total debt, principal amount	$ 1,750	1,750
Interest rate	4.90%
Secured Debt \| 6.10% due July 2027
Debt Instrument [Line Items]
Total debt, principal amount	$ 500	0
Interest rate	6.10%
Secured Debt \| 5.30% due October 2029
Debt Instrument [Line Items]
Total debt, principal amount	$ 1,750	1,750
Interest rate	5.30%
Secured Debt \| 6.20% due July 2030
Debt Instrument [Line Items]
Total debt, principal amount	$ 750	0
Interest rate	6.20%
Secured Debt \| 8.10% due July 2036
Debt Instrument [Line Items]
Total debt, principal amount	$ 1,500	1,500
Interest rate	8.10%
Secured Debt \| 8.35% due July 2046
Debt Instrument [Line Items]
Total debt, principal amount	$ 2,000	2,000
Interest rate	8.35%
Secured Debt \| DFS Debt
Debt Instrument [Line Items]
Total debt, principal amount	$ 8,837	7,765
Total debt, carrying value		7,765
Total short-term debt, carrying value	4,188	4,152
Total long-term debt, carrying value	4,649	3,613
Unsecured Debt \| 4.625% due April 2021
Debt Instrument [Line Items]
Total debt, principal amount	$ 400	400
Interest rate	4.625%
Unsecured Debt \| 7.10% due April 2028
Debt Instrument [Line Items]
Total debt, principal amount	$ 300	300
Interest rate	7.10%
Unsecured Debt \| 6.50% due April 2038
Debt Instrument [Line Items]
Total debt, principal amount	$ 388	388
Interest rate	6.50%
Unsecured Debt \| 5.40% due September 2040
Debt Instrument [Line Items]
Total debt, principal amount	$ 264	264
Interest rate	5.40%
Unsecured Debt \| 5.875% due June 2021
Debt Instrument [Line Items]
Total debt, principal amount	$ 1,075	1,075
Interest rate	5.875%
Unsecured Debt \| 7.125% due June 2024
Debt Instrument [Line Items]
Total debt, principal amount	$ 1,625	1,625
Interest rate	7.125%
Unsecured Debt \| 2.650% due June 2020
Debt Instrument [Line Items]
Total debt, principal amount	$ 0	600	$ 2,000
Interest rate	2.65%
Unsecured Debt \| 3.375% due June 2023
Debt Instrument [Line Items]
Total debt, principal amount	$ 1,000	1,000	$ 1,000
Interest rate	3.375%
Unsecured Debt \| 2.30% due August 2020
Debt Instrument [Line Items]
Total debt, principal amount	$ 0	1,250
Interest rate	2.30%
Unsecured Debt \| 2.95% due August 2022
Debt Instrument [Line Items]
Total debt, principal amount	$ 1,500	1,500
Interest rate	2.95%
Unsecured Debt \| 4.50% due May 2025
Debt Instrument [Line Items]
Total debt, principal amount	$ 750	0
Interest rate	4.50%
Unsecured Debt \| 4.65% due May 2027
Debt Instrument [Line Items]
Total debt, principal amount	$ 500	0
Interest rate	4.65%
Unsecured Debt \| 3.90% due August 2027
Debt Instrument [Line Items]
Total debt, principal amount	$ 1,250	1,250
Interest rate	3.90%
Unsecured Debt \| 4.70% due May 2030
Debt Instrument [Line Items]
Total debt, principal amount	$ 750	0
Interest rate	4.70%
Unsecured Debt \| VMware Term Loan Facility
Debt Instrument [Line Items]
Total debt, principal amount	$ 1,500	1,500
Other
Debt Instrument [Line Items]
Total debt, principal amount	147	84
Other \| 2.51% Margin Loan Facility due April 2022
Debt Instrument [Line Items]
Total debt, principal amount	$ 4,000	$ 4,000
Interest rate at period end	2.51%