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

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- Definition

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

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- Definition

Date the debt instrument was issued, in CCYY-MM-DD format.

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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.

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- Definition

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

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Debt (Unsecured Fixed Rate Debt Securities Issued Under Current Shelf Registration) (Details) - Unsecured Debt [Member] - USD ($)		12 Months Ended
	Jan. 31, 2020	Dec. 31, 2019	Aug. 05, 2019	Feb. 19, 2019
2.950% Notes Due 2022 [Member]
Debt Instrument [Line Items]
Issuance date		Feb. 19, 2019
Note amount				$ 500,000,000
Interest rate on note				2.95%
Maturity date on new borrowing		Mar. 01, 2022
3.150% Notes Due 2024 [Member]
Debt Instrument [Line Items]
Issuance date		Feb. 19, 2019
Note amount				$ 500,000,000
Interest rate on note				3.15%
Maturity date on new borrowing		Mar. 01, 2024
3.700% Notes Due 2029 [Member]
Debt Instrument [Line Items]
Issuance date		Feb. 19, 2019
Note amount				$ 1,000,000,000.0
Interest rate on note				3.70%
Maturity date on new borrowing		Mar. 01, 2029
4.300% Notes Due 2049 [Member]
Debt Instrument [Line Items]
Issuance date		Feb. 19, 2019
Note amount				$ 1,000,000,000.0
Interest rate on note				4.30%
Maturity date on new borrowing		Mar. 01, 2049
3.550% Notes Due 2039 [Member]
Debt Instrument [Line Items]
Issuance date		Aug. 05, 2019
Note amount			$ 500,000,000
Interest rate on note			3.55%
Maturity date on new borrowing		Aug. 15, 2039
3.950% Notes Due 2059 [Member]
Debt Instrument [Line Items]
Issuance date		Aug. 05, 2019
Note amount			$ 500,000,000
Interest rate on note			3.95%
Maturity date on new borrowing		Aug. 15, 2059
Subsequent Event [Member] \| 2.150% Notes Due 2027 [Member]
Debt Instrument [Line Items]
Issuance date	Jan. 31, 2020
Note amount	$ 500,000,000
Interest rate on note	2.15%
Maturity date on new borrowing	Feb. 05, 2027
Subsequent Event [Member] \| 2.400% Notes Due 2030 [Member]
Debt Instrument [Line Items]
Issuance date	Jan. 31, 2020
Note amount	$ 750,000,000
Interest rate on note	2.40%
Maturity date on new borrowing	Feb. 05, 2030
Subsequent Event [Member] \| 3.250% Notes Due 2050 [Member]
Debt Instrument [Line Items]
Issuance date	Jan. 31, 2020
Note amount	$ 1,000,000,000.0
Interest rate on note	3.25%
Maturity date on new borrowing	Feb. 05, 2050
Subsequent Event [Member] \| 3.750% Notes Due 2070 [Member]
Debt Instrument [Line Items]
Issuance date	Jan. 31, 2020
Note amount	$ 750,000,000
Interest rate on note	3.75%
Maturity date on new borrowing	Feb. 05, 2070