A valuation allowance for royalty receivables due to the Company that are expected to be uncollectible.

No definition available.

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

- Definition

Represents impairment charges and allowances.

+ References

No definition available.

+ Details

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Namespace Prefix:	rgld_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Represents the percentage of copper net smelter return.

+ References

No definition available.

+ Details

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

- Definition

Represents percentage of net smelter return.

+ References

No definition available.

+ Details

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

- Definition

Represents the quantity of gold produced or delivered under the terms of the agreement.

+ References

No definition available.

+ Details

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Namespace Prefix:	rgld_
Data Type:	num:massItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of royalty interests acquired by the entity.

+ References

No definition available.

+ Details

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

- Definition

The total amount due to the entity within one year of the balance sheet date relating to royalty contracts.

+ References

No definition available.

+ Details

Name:	rgld_RoyaltyReceivables
Namespace Prefix:	rgld_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 45
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=68055307&loc=d3e2420-110228

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Mineral properties, net of adjustments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 360
-Section 25
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=96866604&loc=d3e64895-109465

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229

+ Details

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

- Details

Name:	us-gaap_CapitalizedCostsOfUnprovedPropertiesExcludedFromAmortizationByPropertyOrProjectAxis=rgld_ProductionStageRoyaltyInterestMember
Namespace Prefix:
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- Details

Name:	us-gaap_CapitalizedCostsOfUnprovedPropertiesExcludedFromAmortizationByPropertyOrProjectAxis=rgld_ExplorationStageRoyaltyInterestMember
Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=rgld_StreamInterestSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=rgld_RoyaltyInterestSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_CapitalizedCostsOfUnprovedPropertiesExcludedFromAmortizationByPropertyOrProjectAxis=rgld_InitialRoyaltyMember
Namespace Prefix:
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- Details

Name:	us-gaap_CapitalizedCostsOfUnprovedPropertiesExcludedFromAmortizationByPropertyOrProjectAxis=rgld_SubsequentRoyaltyMember
Namespace Prefix:
Data Type:	na
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- Details

Name:	us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=rgld_PascuaLamaMember
Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
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- Details

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- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Namespace Prefix:
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Balance Type:
Period Type:

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STREAM AND ROYALTY INTERESTS, NET - Impairments (Details) $ in Thousands		3 Months Ended	12 Months Ended
	Jan. 11, 2016 oz	Mar. 31, 2016 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2017 USD ($)	Dec. 31, 2015 USD ($)
Impairments of royalty and stream interests			$ 239,364	$ 96,118
Impairment of stream and royalty interests and royalty receivables			239,364	98,588
Value of stream and royalty interests, net			2,501,117		$ 2,892,256
Royalty receivables			26,356		26,886
Production stage royalty interests
Value of stream and royalty interests, net			321,613		355,380
Exploration stage royalty interests
Value of stream and royalty interests, net			295,171		152,746
Stream interest
Value of stream and royalty interests, net			1,750,204		1,879,859
Royalty interest
Value of stream and royalty interests, net			$ 990,277		1,012,397
Phoenix Gold
Impairments of royalty and stream interests		$ 77,700
Value of stream and royalty interests, net		0
Phoenix Gold \| Initial Royalty
Royalty interests acquired (as a percent)	6.30%
Gold delivered (in ounces) \| oz	135,000
Phoenix Gold \| Subsequent Royalty
Royalty interests acquired (as a percent)	3.15%
Phoenix Gold \| Stream interest
Impairments of royalty and stream interests				75,702
Pascua-Lama
Copper NSR (as a percent)			1.09%
Pascua-Lama \| Minimum
Net smelter return (NSR) (as a percent)			0.78%
Pascua-Lama \| Maximum
Net smelter return (NSR) (as a percent)			5.45%
Pascua-Lama \| Exploration stage royalty interests
Value of stream and royalty interests, net			$ 177,690
Pascua-Lama \| Royalty interest
Impairments of royalty and stream interests			$ 239,080
Inata
Allowance for royalty receivables				2,855
Royalty interests acquired (as a percent)			2.50%
Value of stream and royalty interests, net		0				$ 12,000
Royalty receivables			$ 2,800
Inata \| Royalty interest
Impairments of royalty and stream interests				11,982
Wolverine
Allowance for royalty receivables				(385)
Value of stream and royalty interests, net		$ 0
Wolverine \| Minimum
Royalty interests acquired (as a percent)			0.00%
Wolverine \| Maximum
Royalty interests acquired (as a percent)			9.445%
Wolverine \| Royalty interest
Impairments of royalty and stream interests				5,307
Other \| Production stage royalty interests
Value of stream and royalty interests, net			$ 119,000		$ 145,685
Other \| Exploration stage royalty interests
Value of stream and royalty interests, net			117,481
Other \| Royalty interest
Impairments of royalty and stream interests			$ 284	$ 3,127