XML 135 R107.htm IDEA: XBRL DOCUMENT v3.21.1

Segmented Information - Narrative (Details)	12 Months Ended
	Dec. 31, 2020 segment
Operating Segments [Abstract]
Number of geographic segments	3

X

- Definition

Number Of Geographic Segments

+ References

No definition available.

+ Details

Name:	cnq_NumberOfGeographicSegments
Namespace Prefix:	cnq_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Operating Segments [Abstract]

+ References

No definition available.

+ Details

Name:	cnq_OperatingSegmentsAbstract
Namespace Prefix:	cnq_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration