ACQUISITION (Details) $ in Millions	Sep. 19, 2016 USD ($)
"Barrick" Cortez mine \| Production stage royalty interests
ACQUISITION
Royalty interest	$ 10.2
"Barrick" Cortez mine \| Development stage royalty interests
ACQUISITION
Royalty interest	$ 59.8
NVR \| "Barrick" Cortez mine
ACQUISITION
Percentage of royalty acquired	3.75%
Total consideration for royalty interest	$ 70.0
NVR \| Cortez Crossroads
ACQUISITION
Ownership interests after acquisition (as a percent)	4.46%
NVR \| Gap deposits
ACQUISITION
Ownership interests after acquisition (as a percent)	4.85%
GSR \| Cortez Crossroads
ACQUISITION
Ownership interests after acquisition (as a percent)	5.00%
GSR \| Gap deposits
ACQUISITION
Ownership interests after acquisition (as a percent)	5.71%

Amount of consideration for royalty interest acquired by the entity.

No definition available.

Name:	rgld_RoyaltyAcquisitionConsideration
Namespace Prefix:	rgld_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Percentage of ownership immediately after all loyalty acquisition transactions.

+ References

No definition available.

+ Details

Name:	rgld_RoyaltyAcquisitionCumulativePercentageOwnershipAfterAllTransactions
Namespace Prefix:	rgld_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of royalty interests acquired by the entity.

+ References

No definition available.

+ Details

Name:	rgld_RoyaltyAcquisitionPercentageOfRoyaltyInterestsAcquired
Namespace Prefix:	rgld_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Carrying amount at the balance sheet date of mineral rights, or rights to extract a mineral from the earth or to receive payment in the form of a royalty for the extraction of minerals, net of amortization.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Mineral Rights
-URI http://asc.fasb.org/extlink&oid=6919630

+ Details

Name:	us-gaap_MineralRights
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=rgld_BarrickGoldCorporationsCortezMineMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CapitalizedCostsOfUnprovedPropertiesExcludedFromAmortizationByPropertyOrProjectAxis=rgld_ProductionStageRoyaltyInterestMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CapitalizedCostsOfUnprovedPropertiesExcludedFromAmortizationByPropertyOrProjectAxis=rgld_DevelopmentStageRoyaltyInterestMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=rgld_NetValueRoyaltyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=rgld_CortezCrossroadsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=rgld_GapDepositsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=rgld_GrossSmelterReturnRoyaltyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: