Exploration and evaluation (Narrative) (Details) - CAD ($) $ in Thousands	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020
Statements Line Items
Impairment	$ 42,668	$ 0
Impairment charge, net of income taxes	$ 34,600

Represents amount of impairment loss reversal of impairment loss assets arising from exploration and evaluation of mineral resources.

No definition available.

Name:	or_ImpairmentLossReversalOfImpairmentLossAssetsArisingFromExplorationAndEvaluationOfMineralResources
Namespace Prefix:	or_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration