Represents the percentage of copper streaming interest.

No definition available.

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

- Definition

Represents the percentage of gold streaming interest.

+ References

No definition available.

+ Details

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

- Definition

Represents the maximum period between the concentrate shipment and final settlement.

+ References

No definition available.

+ Details

Name:	rgld_MaximumPeriodOfSettlementAfterShipment
Namespace Prefix:	rgld_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum purchase price for each payable ounce of gold.

+ References

No definition available.

+ Details

Name:	rgld_MaximumPurchasePriceForEachPayableOunceOfGold
Namespace Prefix:	rgld_
Data Type:	us-types:perUnitItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of Net Smelter Return (“NSR”) royalties received.

+ References

No definition available.

+ Details

Name:	rgld_NumberOfNetSmelterReturnRoyaltiesReceived
Namespace Prefix:	rgld_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents number of shares received that is associated with restructuring activities.

+ References

No definition available.

+ Details

Name:	rgld_NumberOfSharesReceivedOnRestructuring
Namespace Prefix:	rgld_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents percentage of net smelter return.

+ References

No definition available.

+ Details

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

- Definition

Percentage of spot price per metric tonne of copper delivered

+ References

No definition available.

+ Details

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

- Definition

Amount of direct costs of the arrangement including legal, accounting, and other costs incurred.

+ References

No definition available.

+ Details

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

- Definition

Investments in debt and equity securities which are categorized neither as held-to-maturity nor trading and which are intended to be sold or mature more than one year from the balance sheet date or operating cycle, if longer. Such securities are reported at fair value; unrealized gains (losses) related to Available-for-sale Securities are excluded from earnings and reported in a separate component of shareholders' equity (other comprehensive income), unless the Available-for-sale security is designated as a hedge or is determined to have had an other than temporary decline in fair value below its amortized cost basis. All or a portion of the unrealized holding gain (loss) of an Available-for-sale security that is designated as being hedged in a fair value hedge is recognized in earnings during the period of the hedge, as are other than temporary declines in fair value below the cost basis for investments in equity securities and debt securities that an entity intends to sell or it is more likely than not that it will be required to sell before the recovery of its amortized cost basis. Other than temporary declines in fair value below the cost basis for debt securities categorized as Available-for-sale that an entity does not intend to sell and for which it is not more likely than not that the entity will be required to sell before the recovery of its amortized cost basis are bifurcated into credit losses and losses related to all other factors. Other than temporary declines in fair value below cost basis related to credit losses are recognized in earnings, and losses related to all other factors are recognized in other comprehensive income.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=82896770&loc=d3e26626-111562

+ Details

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

- Details

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

- Details

Name:	us-gaap_CounterpartyNameAxis=rgld_RubiconMineralsCorporationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

STREAM AND ROYALTY INTERESTS, NET (Details) shares in Millions, $ in Millions	Dec. 20, 2016 USD ($) item shares	Oct. 20, 2016 USD ($) $ / oz	Oct. 19, 2016	Jun. 30, 2018 USD ($) $ / oz	Jun. 30, 2017 USD ($)
Available-for-sale securities				$ 19.1	$ 3.7
Phoenix Gold \| Rubicon
Number of common shares of Rubicon received \| shares	3
Number of NSR royalties received \| item	3
Net smelter return (NSR) (as a percent)	1.00%
Available-for-sale securities	$ 3.4
Mount Milligan
Gold streaming interest (as a percent)		35.00%	52.25%
Copper streaming interest (as a percent)		18.75%
Cash payment for each ounce of gold (in dollars per ounce) \| $ / oz		435		435
Spot price per delivered metric tonne of copper (as a percent)		15.00%
Maximum period between concentrate shipment and final settlement		5 months
Direct transaction costs		$ 7.7