XML 276 R269.htm IDEA: XBRL DOCUMENT v3.8.0.1

Related undertakings - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2017
Disclosure Of Significant Investments In Subsidiaries [Abstract]
Effective equity holding percentage	50.00%

X

- References

No definition available.

+ Details

Name:	ifrs-full_DisclosureOfSignificantInvestmentsInSubsidiariesAbstract
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Effective group ownership percentage.

+ References

No definition available.

+ Details

Name:	rio_EffectiveGroupOwnershipPercentage
Namespace Prefix:	rio_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration