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 2021-01-01
-Paragraph 55
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_55&doctype=Standard
-URIDate 2021-03-24

+ 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 2021-01-01
-Paragraph 112
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_112_c&doctype=Standard
-URIDate 2021-03-24

+ Details

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

- Definition

The amount of current liabilities that the entity does not separately disclose in the same statement or note. [Refer: Current liabilities]

+ References

+ Details

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

- 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 2021-01-01
-Paragraph 17
-Subparagraph d
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=7&code=ifrs-tx-2021-en-r&anchor=para_17_d&doctype=Standard
-URIDate 2021-03-24

+ Details

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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

- References

No definition available.

+ Details

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

- Definition

It represents increase decrease in settlement of debt.

+ References

No definition available.

+ Details

Name:	ptm_IncreaseDecreaseInSettlementOfDebt
Namespace Prefix:	ptm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- 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		9 Months Ended
SPROTT LOAN (Narrative) (Details) - USD ($) $ in Thousands	Aug. 15, 2019	May 31, 2022	May 31, 2021	Aug. 31, 2021
Sprott Loans [Line Items]
Sprott Facility principal repayments		$ 9,400	$ 8,670
Loan payable		0		$ 9,088
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	1,282
Interest expense on borrowings		378	1,454
Loss on settlement of debt		$ 279	$ 300