Supplementary Information - Condensed Consolidating Financial Information - Cash Flow (Details 2) - USD ($) $ in Millions	9 Months Ended
Sep. 30, 2017	Sep. 30, 2016
Cash Flows From Operating Activities
Net cash provided by (used in) operating activities	$ 4,596	$ 2,960
Cash Flows From Investing Activities
Capital expenditures and investments	(3,074)	(3,870)
Working capital changes associated with investing activities	(18)	(401)
Proceeds from asset dispositions	13,740	419
Net sales (purchases) of short-term investments	(2,583)	(229)
Long-term advances/loans-related parties	0	0
Collection of advances/loans-related parties	115	108
Intercompany cash management	0	0
Other	51	61
Net Cash Provided by (Used in) Investing Activities	8,231	(3,912)
Cash Flows From Financing Activities
Issuance of debt	0	4,594
Repayment of debt	(6,594)	(839)
Issuance of company common stock	(65)	(52)
Repurchase of company common stock	(2,045)	0
Dividends paid	(986)	(940)
Other	(80)	(93)
Net Cash Provided by (Used in) Financing Activities	(9,770)	2,670
Effect of Exchange Rate Changes on Cash and Cash Equivalents	244	4
Net Change in Cash and Cash Equivalents	3,301	1,722
Cash and cash equivalents at beginning of period	3,610	2,368
Cash and Cash Equivalents at End of Period	6,911	4,090
Consolidating Adjustments [Member]
Cash Flows From Operating Activities
Net cash provided by (used in) operating activities	(2,767)	(904)
Cash Flows From Investing Activities
Capital expenditures and investments	867	401
Working capital changes associated with investing activities	0	0
Proceeds from asset dispositions	(14,971)	(2,331)
Net sales (purchases) of short-term investments	0	0
Long-term advances/loans-related parties	94	803
Collection of advances/loans-related parties	(2,866)	(1,024)
Intercompany cash management	0	0
Other	0	0
Net Cash Provided by (Used in) Investing Activities	(16,876)	(2,151)
Cash Flows From Financing Activities
Issuance of debt	(94)	(803)
Repayment of debt	2,866	1,024
Issuance of company common stock	(152)	(174)
Repurchase of company common stock	0
Dividends paid	2,919	1,078
Other	14,104	1,930
Net Cash Provided by (Used in) Financing Activities	19,643	3,055
Effect of Exchange Rate Changes on Cash and Cash Equivalents	0	0
Net Change in Cash and Cash Equivalents	0	0
Cash and cash equivalents at beginning of period	0	0
Cash and Cash Equivalents at End of Period	0	0
ConocoPhillips [Member]
Cash Flows From Operating Activities
Net cash provided by (used in) operating activities	(161)	(315)
Cash Flows From Investing Activities
Capital expenditures and investments	0	0
Working capital changes associated with investing activities	0	0
Proceeds from asset dispositions	5,000	2,300
Net sales (purchases) of short-term investments	0	0
Long-term advances/loans-related parties	0	0
Collection of advances/loans-related parties	658	0
Intercompany cash management	2,903	(2,767)
Other	0	0
Net Cash Provided by (Used in) Investing Activities	8,561	(467)
Cash Flows From Financing Activities
Issuance of debt	0	1,600
Repayment of debt	(5,459)	0
Issuance of company common stock	87	122
Repurchase of company common stock	(2,045)
Dividends paid	(986)	(940)
Other	3	0
Net Cash Provided by (Used in) Financing Activities	(8,400)	782
Effect of Exchange Rate Changes on Cash and Cash Equivalents	0	0
Net Change in Cash and Cash Equivalents	0	0
Cash and cash equivalents at beginning of period	0	0
Cash and Cash Equivalents at End of Period	0	0
ConocoPhillips Company [Member]
Cash Flows From Operating Activities
Net cash provided by (used in) operating activities	634	(124)
Cash Flows From Investing Activities
Capital expenditures and investments	(1,230)	(889)
Working capital changes associated with investing activities	36	(135)
Proceeds from asset dispositions	10,974	175
Net sales (purchases) of short-term investments	0	0
Long-term advances/loans-related parties	(74)	(803)
Collection of advances/loans-related parties	127	60
Intercompany cash management	(2,474)	2,272
Other	0	3
Net Cash Provided by (Used in) Investing Activities	7,359	683
Cash Flows From Financing Activities
Issuance of debt	20	2,994
Repayment of debt	(3,146)	(964)
Issuance of company common stock	0	0
Repurchase of company common stock	0
Dividends paid	0	0
Other	(5,000)	(2,318)
Net Cash Provided by (Used in) Financing Activities	(8,126)	(288)
Effect of Exchange Rate Changes on Cash and Cash Equivalents	1	0
Net Change in Cash and Cash Equivalents	(132)	271
Cash and cash equivalents at beginning of period	358	4
Cash and Cash Equivalents at End of Period	226	275
ConocoPhillips Canada Funding Company I [Member]
Cash Flows From Operating Activities
Net cash provided by (used in) operating activities	22	(4)
Cash Flows From Investing Activities
Capital expenditures and investments	0	0
Working capital changes associated with investing activities	0	0
Proceeds from asset dispositions	0	0
Net sales (purchases) of short-term investments	0	0
Long-term advances/loans-related parties	0	0
Collection of advances/loans-related parties	0	0
Intercompany cash management	0	0
Other	0	0
Net Cash Provided by (Used in) Investing Activities	0	0
Cash Flows From Financing Activities
Issuance of debt	0	0
Repayment of debt	0	0
Issuance of company common stock	0	0
Repurchase of company common stock	0
Dividends paid	0	0
Other	0	0
Net Cash Provided by (Used in) Financing Activities	0	0
Effect of Exchange Rate Changes on Cash and Cash Equivalents	0	0
Net Change in Cash and Cash Equivalents	22	(4)
Cash and cash equivalents at beginning of period	13	15
Cash and Cash Equivalents at End of Period	35	11
All Other Subsidiaries [Member]
Cash Flows From Operating Activities
Net cash provided by (used in) operating activities	6,868	4,307
Cash Flows From Investing Activities
Capital expenditures and investments	(2,711)	(3,382)
Working capital changes associated with investing activities	(54)	(266)
Proceeds from asset dispositions	12,737	275
Net sales (purchases) of short-term investments	(2,583)	(229)
Long-term advances/loans-related parties	(20)	0
Collection of advances/loans-related parties	2,196	1,072
Intercompany cash management	(429)	495
Other	51	58
Net Cash Provided by (Used in) Investing Activities	9,187	(1,977)
Cash Flows From Financing Activities
Issuance of debt	74	803
Repayment of debt	(855)	(899)
Issuance of company common stock	0	0
Repurchase of company common stock	0
Dividends paid	(2,919)	(1,078)
Other	(9,187)	295
Net Cash Provided by (Used in) Financing Activities	(12,887)	(879)
Effect of Exchange Rate Changes on Cash and Cash Equivalents	243	4
Net Change in Cash and Cash Equivalents	3,411	1,455
Cash and cash equivalents at beginning of period	3,239	2,349
Cash and Cash Equivalents at End of Period	$ 6,650	$ 3,804

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The net amount paid (received) by the reporting entity through acquisition (sale/maturities) of short-term investments in bank time deposits and marketable securities (commercial paper and government obligations) with original maturities of less than one year.

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Amount of cash inflow (outflow) from financing activities, including discontinued operations. Financing activity cash flows include obtaining resources from owners and providing them with a return on, and a return of, their investment; borrowing money and repaying amounts borrowed, or settling the obligation; and obtaining and paying for other resources obtained from creditors on long-term credit.

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Amount of cash inflow (outflow) from investing activities, including discontinued operations. Investing activity cash flows include making and collecting loans and acquiring and disposing of debt or equity instruments and property, plant, and equipment and other productive assets.

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The cash outflow for purchases of and capital improvements on property, plant and equipment (capital expenditures), software, and other intangible assets.

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The cash outflow associated with extending a long-term loan to a related party. Alternate caption: Payments for Advances to Affiliates.

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