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 2020-01-01
-Paragraph 21
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=24&code=ifrs-tx-2020-en-r&anchor=para_21_c&doctype=Standard
-URIDate 2020-01-01

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

Represents the amount of common shares acquired from public market.

No definition available.

Name:	ptm_CommonSharesAcquiredFromPublicMarket
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

It represents Number of shares sold by another entity.

No definition available.

Name:	ptm_NumberOfSharesSoldByAnotherEntity
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.