Face (par) amount of debt instrument at time of issuance.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399

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Period Type:	instant

- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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Balance Type:	na
Period Type:	instant

- Definition

The cash inflow from a debt initially having maturity due after one year or beyond the operating cycle, if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3255-108585

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- Definition

[Line Items] for Schedule of Fiscal Year 2018 Debt Issuances [Table]

+ References

No definition available.

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Short-term Borrowings and Long-term Debt (Schedule of Fiscal Year 2018 Debt Issuances) (Details) ¥ in Millions, $ in Millions			12 Months Ended
	Oct. 20, 2017 USD ($)	Jul. 18, 2017 USD ($)	Jan. 31, 2018 USD ($)	Jan. 31, 2017 USD ($)	Jan. 31, 2016 USD ($)	Jul. 18, 2017 JPY (¥)
Schedule of Fiscal Year 2018 Debt Issuances [Line Items]
Proceeds from issuance of long-term debt			$ 7,476	$ 137	$ 39
0.183% Debt Issuance, Due 2022 [Domain] \| Unsecured debt
Schedule of Fiscal Year 2018 Debt Issuances [Line Items]
Principal amount \| ¥						¥ 70,000
Interest rate						0.183%
Proceeds from issuance of long-term debt		$ 619
0.298% Debt Issuance, Due 2024 [Domain] \| Unsecured debt
Schedule of Fiscal Year 2018 Debt Issuances [Line Items]
Principal amount \| ¥						¥ 40,000
Interest rate						0.298%
Proceeds from issuance of long-term debt		354
0.520% Debt Issuance, Due 2027 [Domain] \| Unsecured debt
Schedule of Fiscal Year 2018 Debt Issuances [Line Items]
Principal amount \| ¥						¥ 60,000
Interest rate						0.52%
Proceeds from issuance of long-term debt		$ 530
Variable Rate Debt, Due 2019 [Domain] \| Unsecured debt
Schedule of Fiscal Year 2018 Debt Issuances [Line Items]
Principal amount	$ 300
Proceeds from issuance of long-term debt	299
1.75% Debt Issuance, Due 2019 [Domain] \| Unsecured debt
Schedule of Fiscal Year 2018 Debt Issuances [Line Items]
Principal amount	$ 1,200
Interest rate	1.75%
Proceeds from issuance of long-term debt	$ 1,198
1.900% Debt Issuance, Due 2020 [Domain] \| Unsecured debt
Schedule of Fiscal Year 2018 Debt Issuances [Line Items]
Principal amount	$ 1,250
Interest rate	1.90%
Proceeds from issuance of long-term debt	$ 1,245
2.350% Debt Issuance, Due 2022 [Domain] \| Unsecured debt
Schedule of Fiscal Year 2018 Debt Issuances [Line Items]
Principal amount	$ 1,250
Interest rate	2.35%
Proceeds from issuance of long-term debt	$ 1,245
2.650% Debt Issuance, Due 2024 [Domain] \| Unsecured debt
Schedule of Fiscal Year 2018 Debt Issuances [Line Items]
Principal amount	$ 1,000
Interest rate	2.65%
Proceeds from issuance of long-term debt	$ 996
3.625% Debt Issuance, Due 2047 [Domain] \| Unsecured debt
Schedule of Fiscal Year 2018 Debt Issuances [Line Items]
Principal amount	$ 1,000
Interest rate	3.625%
Proceeds from issuance of long-term debt	$ 990