v3.25.2

Share-based compensation (Narrative) (Details) $ / shares in Units, $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2025 $ / shares | Dec. 31, 2025 USD ($) $ / shares | Dec. 31, 2024 $ / shares | Dec. 31, 2024 USD ($)
Disclosure of terms and conditions of share-based payment arrangement [line items] |  |  |  |
Weighted average share price | $ / shares | $ 32.41 |  | $ 23.59 |
Share-based compensation related to share options |  | $ 0.7 |  | $ 1.6
Deferred share units [Member] |  |  |  |
Disclosure of terms and conditions of share-based payment arrangement [line items] |  |  |  |
Weighted average value of deferred share units granted | $ / shares | 34.01 |  | 21.84 |
Restricted share units ("RSU") [Member] |  |  |  |
Disclosure of terms and conditions of share-based payment arrangement [line items] |  |  |  |
Weighted average value of restricted share units granted | $ / shares | 26.68 |  | $ 18.79 |
DSU and RSU [Member] |  |  |  |
Disclosure of terms and conditions of share-based payment arrangement [line items] |  |  |  |
Share-based compensation |  | $ 7.7 |  | 4.7
Closing price of the common shares | (per share) | $ 48.62 | $ 35.39 |  |
Marginal income tax rate |  | 53.30% |  |
Employees tax obligations settlement amount related to vested RSU and DSU |  | $ 5.6 |  | 3.7
Employees tax obligations settlement amount related to outstanding RSU and DSU |  | $ 21.2 |  | $ 11.4

X
- Definition Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table. + References No definition available. + Details
Name: | ifrs-full_DisclosureOfTermsAndConditionsOfSharebasedPaymentArrangementLineItems
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The weighted average share price. [Refer: Weighted average [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 2 -IssueDate 2025-01-01 -Paragraph 45 -Subparagraph c -URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2025-en-r&anchor=para_45_c&doctype=Standard -URIDate 2025-03-27 + Details
Name: | ifrs-full_WeightedAverageSharePrice2019
Namespace Prefix: | ifrs-full_
Data Type: | dtr-2022:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the closing prices of common shares. + References No definition available. + Details
Name: | or_ClosingPricesOfCommonShares
Namespace Prefix: | or_
Data Type: | dtr-types:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Employees tax obligations settlement amount related to outstanding restricted share units and deferred share units. + References No definition available. + Details
Name: | or_EmployeesTaxObligationsSettlementAmountRelatedToOutstandingRestrictedShareUnitsAndDeferredShareUnits
Namespace Prefix: | or_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Employees tax obligations settlement amount related to vested restricted share units and deferred share units. + References No definition available. + Details
Name: | or_EmployeesTaxObligationsSettlementAmountRelatedToVestedRestrictedShareUnitsAndDeferredShareUnits
Namespace Prefix: | or_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Marginal income tax rate. + References No definition available. + Details
Name: | or_MarginalIncomeTaxRate
Namespace Prefix: | or_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Share-based compensation related to share options + References No definition available. + Details
Name: | or_ShareBasedCompensationRelatedToShareOptions
Namespace Prefix: | or_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Share-based compensation + References No definition available. + Details
Name: | or_ShareBasedCompensations
Namespace Prefix: | or_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Weighted average value of deferred shares units granted. + References No definition available. + Details
Name: | or_WeightedAverageValueDeferredSharesUnitsGranted
Namespace Prefix: | or_
Data Type: | dtr-types:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Weighted average value restricted stock units granted. + References No definition available. + Details
Name: | or_WeightedAverageValueRestrictedStockUnitsGranted
Namespace Prefix: | or_
Data Type: | dtr-types:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | ifrs-full_ClassesOfProvisionsAxis=or_DeferredShareUnitsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfProvisionsAxis=or_RestrictedShareUnitMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfProvisionsAxis=or_DeferredShareUnitsAndRestrictedShareUnitsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |