Description of Business and Summary of Significant Accounting Policies - Components of Other Insurance Liabilities, Current (Details) $ in Thousands	Sep. 30, 2021 USD ($)
Description of Business and Summary of Significant Accounting Policies
Ceded reinsurance premiums payable	$ 18,922
Funds held under reinsurance treaty	2,600
Commissions payable, reinsurers and agents	9,453
General and accrued expenses payable	537
Advance premiums	3,307
Other insurance liabilities, current	$ 34,819

Amount of insurance liabilities classified as other, due within one year or the normal operating cycle, if longer.

No definition available.

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Namespace Prefix:	prch_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The amount of commission payable to reinsurers and agents as at the end of the reporting period.

+ References

No definition available.

+ Details

Name:	prch_ReinsuranceAndAgentsCommissionPayable
Namespace Prefix:	prch_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- References

No definition available.

+ Details

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

- Definition

Sum of the carrying values as of the balance sheet date of obligations incurred through that date and due within one year (or the operating cycle, if longer), including liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received, taxes, interest, rent and utilities, accrued salaries and bonuses, payroll taxes and fringe benefits.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19,20)
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

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

- Definition

The consideration due to the assuming enterprise as of the balance sheet date under the terms of the reinsurance contract in exchange for the right to receive reimbursement from such entity for covered claims and expenses.

+ References

No definition available.

+ Details

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

- Definition

Amount of funds held as security for payments to be received under reinsurance contracts.

+ References

No definition available.

+ Details

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

- Definition

The carrying amount as of the balance sheet date of the known and estimated amounts owed to insurers under reinsurance treaties or other arrangements.

+ References

No definition available.

+ Details

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