Name:	ifrs-full_DisclosureOfTransactionsBetweenRelatedPartiesLineItems
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

The amount of revenue arising from the rendering of services in related party transactions. [Refer: Revenue; Related parties [member]]

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Name IAS
-Number 24
-IssueDate 2021-01-01
-Paragraph 21
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=24&code=ifrs-tx-2021-en-r&anchor=para_21_c&doctype=Standard
-URIDate 2021-03-24

Name:	ifrs-full_RevenueFromRenderingOfServicesRelatedPartyTransactions
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The amount of remuneration paid or payable to the entity's directors.

No definition available.

Name:	ptm_AmountOfAccruedIndependentDirectorsFeesAndServices
Namespace Prefix:	ptm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Equity Issuance, Price per Share

No definition available.

Name:	ptm_EquityIssuancePricePerShare
Namespace Prefix:	ptm_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	duration

The amount of gross proceeds from private placement.

No definition available.

Name:	ptm_GrossProceedsFromPrivatePlacement
Namespace Prefix:	ptm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Information about increase decrease through shares issued for on convertible note.

No definition available.

Name:	ptm_IncreaseDecreaseThroughSharesIssuedOnConvertibleNote
Namespace Prefix:	ptm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Represents the number of common shares issued for private placement.

No definition available.

Name:	ptm_NumberOfCommonSharesIssuedForPrivatePlacement
Namespace Prefix:	ptm_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

Represents number of shares owned.

No definition available.

Name:	ptm_NumberOfSharesOwned
Namespace Prefix:	ptm_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

The proportion of ownership interest of the Company held by another entity.

No definition available.

Name:	ptm_ProportionOfEntityInterestHeldByAnotherEntity
Namespace Prefix:	ptm_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

Name:	ifrs-full_BorrowingsByNameAxis=ptm_ConvertibleNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	ifrs-full_CategoriesOfRelatedPartiesAxis=ptm_WestKirklandMiningIncMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	ifrs-full_CategoriesOfRelatedPartiesAxis=ptm_HoskenConsolidatedInvestmentsLimitedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: