Amount of short-term and long-term debt and lease obligation.

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Description of the credit rating indicative of likelihood of repayment of the debt instrument given by a credit rating agency (for example, Standard and Poor's, Moody's, Fitch).

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

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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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The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

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The maximum amount of borrowing capacity under a line of credit that is available as of the balance sheet date for a specific purpose other than for financing goods acquired for inventory or imminent delivery to a customer.

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Date the credit facility terminates, in CCYY-MM-DD format.

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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

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The cash inflow from borrowing by issuing commercial paper.

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Description of the short-term debt arrangement, and disclosures pertaining to the underlying arrangements, including repayment terms, interest rates, restrictions on assets and activities, debt covenants, and other matters important to users of the financial statements.

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Debt - Textual (Details) - USD ($)	1 Months Ended	3 Months Ended	9 Months Ended
Debt - Textual (Details) - USD ($)	Oct. 31, 2020	Sep. 30, 2020	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Debt [Abstract]
Debt balance		$ 15,387,000,000	$ 15,387,000,000		$ 14,895,000,000
Short Term Debt [Line Items]
Proceeds from Issuance of Commercial Paper		300,000,000	300,000,000	$ 0
Commercial Paper Program, Amount Outstanding		240,000,000	$ 240,000,000
Moody's, A3 Rating [Member]
Debt Instrument [Line Items]
Debt Instrument, Credit Rating			and Moody’s affirmed its rating of “A3” with a “stable” outlook.
Fitch, A Rating [Member] \| Subsequent Event [Member]
Debt Instrument [Line Items]
Debt Instrument, Credit Rating	Fitch affirmed its rating of “A” with a “stable” outlook
Standard & Poor's, A Rating [Member] \| Subsequent Event [Member]
Debt Instrument [Line Items]
Debt Instrument, Credit Rating	In October 2020, S&P affirmed its “A” rating on our senior long-term debt and revised its outlook to “stable” from “negative,”
Revolving Credit Facility [Member]
Short Term Debt [Line Items]
Maximum borrowing capactiy under revolving credit facility		6,000,000,000.0	$ 6,000,000,000.0
Line of Credit Facility, Expiration Date			May 31, 2023
Remaining borrowing capacity under revolving credit facility		5,700,000,000	$ 5,700,000,000
Commercial Paper Program, Amount Outstanding		0	0		0
Letter of Credit [Member]
Short Term Debt [Line Items]
Commercial Paper Program, Amount Outstanding		0	0		0
Letter of Credit [Member] \| Maximum [Member]
Short Term Debt [Line Items]
Commercial Paper Program, Capacity		500,000,000	500,000,000
VRDB [Member]
Debt Instrument [Line Items]
Debt Instrument Face Amount		283,000,000	283,000,000
Conoco Phillips Commercial Paper Program [Member] \| Commercial Paper [Member]
Short Term Debt [Line Items]
Maximum borrowing capactiy under revolving credit facility		6,000,000,000.0	6,000,000,000.0
Commercial Paper Program, Amount Outstanding		$ 300,000,000	$ 300,000,000		$ 0
Conoco Phillips Commercial Paper Program [Member] \| Commercial Paper [Member] \| Maximum [Member]
Short Term Debt [Line Items]
Maturity period of commercial paper (in days)			P90D