The amount of outstanding funds that the entity is obligated to repay.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2022-03-24
-Paragraph 55
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2022-en-r&anchor=para_55&doctype=Standard
-URIDate 2022-03-24

+ Details

Name:	ifrs-full_Borrowings
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The amount of interest expense on borrowings. [Refer: Interest expense; Borrowings]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2022-03-24
-Paragraph 112
-Subparagraph c
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2022-en-r&anchor=para_112_c&doctype=Standard
-URIDate 2022-03-24

+ Details

Name:	ifrs-full_InterestExpenseOnBorrowings
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The cash outflow to settle borrowings, classified as financing activities. [Refer: Borrowings]

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Name IAS
-Number 7
-IssueDate 2022-03-24
-Paragraph 17
-Subparagraph d
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=7&code=ifrs-tx-2022-en-r&anchor=para_17_d&doctype=Standard
-URIDate 2022-03-24

+ Details

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

- Definition

Reprsents amount of advanced principal senior secured credit facility.

+ References

No definition available.

+ Details

Name:	ptm_AdvancedAmountOfPrincipalSeniorSecuredCreditFacility
Namespace Prefix:	ptm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Borrowings extended amount.

+ References

No definition available.

+ Details

Name:	ptm_BorrowingsExtendedAmount
Namespace Prefix:	ptm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Represents percentage of loan facility, interest rate.

+ References

No definition available.

+ Details

Name:	ptm_LoanFacilityInterestRate
Namespace Prefix:	ptm_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents amount of payment for monthly interest charge.

+ References

No definition available.

+ Details

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

- Definition

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.

+ References

No definition available.

+ Details

Name:	ptm_SprottLoansLineItems
Namespace Prefix:	ptm_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

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

SPROTT LOAN (Narrative) (Details) - USD ($) $ in Thousands		12 Months Ended
SPROTT LOAN (Narrative) (Details) - USD ($) $ in Thousands	Aug. 15, 2019	Aug. 31, 2022	Aug. 31, 2021	Aug. 31, 2020
Sprott Loans [Line Items]
Repayments of principal amount		$ 9,400	$ 10,600	$ 0
Sprott Facility [Member]
Sprott Loans [Line Items]
Advanced amount of principal senior secured credit facility	$ 20,000
Loan facility interest rate	11% per annum, compounded monthly
Borrowings extended amount			10,000
Principal amount outstanding		0	9,400
Payment for monthly interest charge		293	1,590
Interest expense on borrowings		378	2,120
Repayments of principal amount		$ 279	$ 189