Environmental and Other Contingencies - Narrative (Details) $ in Millions	Dec. 31, 2020 USD ($)
Environmental Remediation Obligations [Abstract]
Threshold for disclosure of monetary sanctions related to environmental proceedings	$ 1

Threshold For Disclosure Of Monetary Sanctions, Environmental Proceedings

No definition available.

Name:	mur_ThresholdForDisclosureOfMonetarySanctionsEnvironmentalProceedings
Namespace Prefix:	mur_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant