Price per share or per unit of warrants or rights outstanding.

No definition available.

Name:	pmgmu_ClassOfWarrantOrRightPriceOfWarrantsOrRights
Namespace Prefix:	pmgmu_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of maximum borrowing capacity of related party promissory note.

+ References

No definition available.

+ Details

Name:	pmgmu_MaximumBorrowingCapacityOfRelatedPartyPromissoryNote
Namespace Prefix:	pmgmu_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The maximum amount which a potential loan could have repaid through issuance of warrants.

+ References

No definition available.

+ Details

Name:	pmgmu_MaximumLoansConvertibleIntoWarrants
Namespace Prefix:	pmgmu_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The contractual monthly amount to be paid for support services.

+ References

No definition available.

+ Details

Name:	pmgmu_RelatedPartyTransactionExpensesFromTransactionsWithRelatedPartyPerMonth
Namespace Prefix:	pmgmu_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Represents the amount of working capital loan.

+ References

No definition available.

+ Details

Name:	pmgmu_WorkingCapitalLoans
Namespace Prefix:	pmgmu_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The amount for notes payable (written promise to pay), due to related parties. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(k)(1))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
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-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(a)(5))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

Name:	us-gaap_NotesPayableRelatedPartiesClassifiedCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The amount for notes payable (written promise to pay), due to related parties.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.17)
-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

+ Details

Name:	us-gaap_NotesPayableRelatedPartiesCurrentAndNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

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

+ References

No definition available.

+ Details

Name:	us-gaap_RelatedPartyTransactionLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The cash outflow for the payment of a long-term borrowing made from a related party where one party can exercise control or significant influence over another party; including affiliates, owners or officers and their immediate families, pension trusts, and so forth. Alternate caption: Payments for Advances from Affiliates.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3291-108585

+ Details

Name:	us-gaap_RepaymentsOfRelatedPartyDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=pmgmu_SponsorMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=pmgmu_PromissoryNoteWithRelatedPartyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=pmgmu_WorkingCapitalLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=pmgmu_AdministrativeServiceFeeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Related Party Transactions - Additional Information (Details) - USD ($)			3 Months Ended
	Feb. 08, 2021	Jan. 13, 2021	Mar. 31, 2021	Feb. 11, 2021	Dec. 31, 2020	Dec. 17, 2020
Related Party Transaction [Line Items]
Maximum borrowing capacity of related party promissory note			$ 41,965
Outstanding balance of related party note			50,000
Sponsor
Related Party Transaction [Line Items]
Promissory note - Related party				$ 73,295
Promissory Note with Related Party
Related Party Transaction [Line Items]
Maximum borrowing capacity of related party promissory note						$ 75,000
Repayment of promissory note - related party		$ 50,000
Promissory note - Related party			0		$ 38,588
Working Capital Loans
Related Party Transaction [Line Items]
Loan conversion agreement warrant			$ 1,500,000
Price of warrant			$ 1.50
Working capital loans			$ 100,000			$ 0
Administrative Service Fee
Related Party Transaction [Line Items]
Expenses per month	$ 25,000
Outstanding balance of related party note			15,000
Administrative Service Fee \| Sponsor
Related Party Transaction [Line Items]
Expenses per month			$ 10,000