Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes of the table.

No definition available.

+ Details

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

- Definition

The proportion of ownership interests in a subsidiary held by non-controlling interests. [Refer: Subsidiaries [member]; Non-controlling interests]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 12
-IssueDate 2020-01-01
-Paragraph 12
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2020-en-r&anchor=para_12_c&doctype=Standard
-URIDate 2020-01-01

+ Details

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Namespace Prefix:	ifrs-full_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The cash outflow for repayments of current borrowings. [Refer: Current borrowings]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 7
-IssueDate 2020-01-01
-Paragraph 17
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=7&code=ifrs-tx-2020-en-r&anchor=para_17&doctype=Standard
-URIDate 2020-01-01

+ Details

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

- Definition

Represents amount of minimum operating lease payment.

+ References

No definition available.

+ Details

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

- Details

Name:	ifrs-full_SignificantInvestmentsInSubsidiariesAxis=ptm_MaseveInvestmentsOneOnePtyLtdMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ptm_FeeAndCommissionAxis=ptm_BrokerageFeesPayableMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_CategoriesOfRelatedPartiesAxis=ptm_LibertyMetalsAndMiningHoldingsLlcMember
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CONTINGENCIES AND COMMITMENTS (Narrative) (Details) - USD ($) $ in Thousands	1 Months Ended		12 Months Ended
	Aug. 21, 2019	Apr. 30, 2018	Aug. 31, 2021
Disclosure of contingent liabilities [line items]
Minimum operating lease payments			$ 282
Maseve Investments 11 (Pty) Ltd. [Member]
Disclosure of contingent liabilities [line items]
Proportion of ownership and voting rights held by non-controlling interests		17.10%
Brokerage Fees Payable [Member] \| LMM Facility [Member]
Disclosure of contingent liabilities [line items]
Repayment of secured loan facility	$ 40,000