Supplementary Information - Condensed Consolidating Financial Information - Bal Sheet (Details Textual) (USD $) In Billions, unless otherwise specified	Apr. 30, 2014
ConocoPhillips [Member]
Condensed Financial Statements, Captions [Line Items]
Intercompany dividend	$ 32
ConocoPhillips Company [Member]
Condensed Financial Statements, Captions [Line Items]
Intercompany dividend	$ (32)

Dividend from ConocoPhillips Company to ConocoPhillips to settle certain accumulated intercompany balances. No impact to consolidated financial statements.

No definition available.

Name:	cop_IntercompanySettlement
Namespace Prefix:	cop_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant