Supplementary Information - Condensed Consolidating Financial Information - Cash Flow (Details 2) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2016	Mar. 31, 2015
Cash Flows From Operating Activities
Net Cash Provided by (Used in) Operating Activities		$ 421	$ 2,068	[1]
Cash Flows From Investing Activities
Capital expenditures and investments		(1,821)	(3,332)	[1]
Working capital changes associated with investing activities		(134)	(198)	[1]
Proceeds from asset dispositions		135	173	[1]
Net sales (purchases) of short-term investments		(302)
Collection of advances/loans-related parties		53	52	[1]
Other		4	(9)	[1]
Net Cash Provided by (Used in) Investing Activities		(2,065)	(3,314)	[1]
Cash Flows From Financing Activities
Issuance of debt		4,594
Repayment of debt		(64)	(57)	[1]
Issuance of company common stock		(42)	(34)	[1]
Dividends paid		(313)	(910)	[1]
Other		(38)	(18)	[1]
Net Cash Provided by (Used in) Financing Activities		4,137	(1,019)	[1]
Effect of Exchange Rate Changes on Cash and Cash Equivalents		5	(133)	[1]
Net Change in Cash and Cash Equivalents		2,498	(2,398)	[1]
Cash and cash equivalents at beginning of period		2,368	5,062	[1]
Cash and Cash Equivalents at End of Period		4,866	2,664	[1]
ConocoPhillips [Member]
Cash Flows From Operating Activities
Net Cash Provided by (Used in) Operating Activities		(153)	(131)	[1]
Cash Flows From Investing Activities
Capital expenditures and investments	[1]		0
Working capital changes associated with investing activities	[1]		0
Proceeds from asset dispositions		2,300	0	[1]
Net sales (purchases) of short-term investments	[1]		0
Long-term advances/loans-related parties	[1]		0
Collection of advances/loans-related parties	[1]		0
Intercompany cash management		(3,438)	974	[1]
Other	[1]		0
Net Cash Provided by (Used in) Investing Activities		(1,138)	974	[1]
Cash Flows From Financing Activities
Issuance of debt		1,600
Repayment of debt		0	0	[1]
Issuance of company common stock		7	66	[1]
Dividends paid		(313)	(910)	[1]
Other		(3)	1	[1]
Net Cash Provided by (Used in) Financing Activities		1,291	(843)	[1]
Net Change in Cash and Cash Equivalents	[1]		0
ConocoPhillips Company [Member]
Cash Flows From Operating Activities
Net Cash Provided by (Used in) Operating Activities		(284)	(231)	[1]
Cash Flows From Investing Activities
Capital expenditures and investments		(504)	(941)	[1]
Working capital changes associated with investing activities		(21)	60	[1]
Proceeds from asset dispositions		60	88	[1]
Net sales (purchases) of short-term investments	[1]		0
Long-term advances/loans-related parties		(51)	(72)	[1]
Collection of advances/loans-related parties		0	0	[1]
Intercompany cash management		3,206	(1,085)	[1]
Other		8	(7)	[1]
Net Cash Provided by (Used in) Investing Activities		2,698	(1,957)	[1]
Cash Flows From Financing Activities
Issuance of debt		2,994	1,482	[1]
Repayment of debt		(2,145)	0	[1]
Issuance of company common stock	[1]		0
Dividends paid		0	0	[1]
Other		(2,320)	0	[1]
Net Cash Provided by (Used in) Financing Activities		(1,471)	1,482	[1]
Net Change in Cash and Cash Equivalents		943	(706)	[1]
Cash and cash equivalents at beginning of period		4	770
Cash and Cash Equivalents at End of Period		947	64	[1]
ConocoPhillips Canada Funding Company I [Member]
Cash Flows From Operating Activities
Net Cash Provided by (Used in) Operating Activities		1	1	[1]
Cash Flows From Investing Activities
Capital expenditures and investments	[1]		0
Working capital changes associated with investing activities	[1]		0
Proceeds from asset dispositions	[1]		0
Net sales (purchases) of short-term investments	[1]		0
Long-term advances/loans-related parties	[1]		0
Collection of advances/loans-related parties	[1]		0
Intercompany cash management	[1]		0
Other	[1]		0
Net Cash Provided by (Used in) Investing Activities	[1]		0
Cash Flows From Financing Activities
Repayment of debt	[1]		0
Issuance of company common stock	[1]		0
Dividends paid	[1]		0
Other	[1]		0
Net Cash Provided by (Used in) Financing Activities	[1]		0
Net Change in Cash and Cash Equivalents		1	1	[1]
Cash and cash equivalents at beginning of period		15	7
Cash and Cash Equivalents at End of Period		16	8	[1]
All Other Subsidiaries [Member]
Cash Flows From Operating Activities
Net Cash Provided by (Used in) Operating Activities		1,011	2,340	[1]
Cash Flows From Investing Activities
Capital expenditures and investments		(1,516)	(2,759)	[1]
Working capital changes associated with investing activities		(113)	(258)	[1]
Proceeds from asset dispositions		75	88	[1]
Net sales (purchases) of short-term investments		(302)	0	[1]
Long-term advances/loans-related parties		0	(1,482)	[1]
Collection of advances/loans-related parties		2,198	52	[1]
Intercompany cash management		232	111	[1]
Other		(4)	(2)	[1]
Net Cash Provided by (Used in) Investing Activities		570	(4,250)	[1]
Cash Flows From Financing Activities
Issuance of debt		51	72	[1]
Repayment of debt		(64)	(57)	[1]
Issuance of company common stock	[1]		0
Dividends paid		(203)	(11)	[1]
Other		184	346	[1]
Net Cash Provided by (Used in) Financing Activities		(32)	350	[1]
Effect of Exchange Rate Changes on Cash and Cash Equivalents		5	(133)	[1]
Net Change in Cash and Cash Equivalents		1,554	(1,693)	[1]
Cash and cash equivalents at beginning of period		2,349	4,285
Cash and Cash Equivalents at End of Period		3,903	2,592	[1]
Consolidating Adjustments [Member]
Cash Flows From Operating Activities
Net Cash Provided by (Used in) Operating Activities		(154)	89
Cash Flows From Investing Activities
Capital expenditures and investments		199	368	[1]
Working capital changes associated with investing activities	[1]		0
Proceeds from asset dispositions		(2,300)	(3)	[1]
Net sales (purchases) of short-term investments	[1]		0
Long-term advances/loans-related parties		51	1,554	[1]
Collection of advances/loans-related parties		(2,145)	0	[1]
Intercompany cash management	[1]		0
Other	[1]		0
Net Cash Provided by (Used in) Investing Activities		(4,195)	1,919	[1]
Cash Flows From Financing Activities
Issuance of debt		(51)	(1,554)	[1]
Repayment of debt		2,145	0	[1]
Issuance of company common stock		(49)	(100)	[1]
Dividends paid		203	11	[1]
Other		2,101	(365)	[1]
Net Cash Provided by (Used in) Financing Activities		$ 4,349	(2,008)	[1]
Net Change in Cash and Cash Equivalents	[1]		$ 0

[1] *Certain amounts have been reclassified to conform to current-period presentation. See Note 16–Cash Flow Information, in the Notes to Consolidated Financial Statements.See Notes to Consolidated Financial Statements.