Debt, Long-term and Short-term, Combined Amount, Gross

No definition available.

Name:	pra_DebtLongTermAndShortTermCombinedAmountGross
Namespace Prefix:	pra_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

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+ Details

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

- Definition

Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable.

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+ Details

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

- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentTerm
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount, after accumulated amortization, of debt premium.

+ References

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+ Details

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

- Definition

The cash outflow to repay long-term debt that is wholly or partially secured by collateral. Excludes repayments of tax exempt secured debt.

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+ Details

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

- Details

Name:	us-gaap_BusinessAcquisitionAxis=pra_NORCALGroupMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=pra_ContributionCertificateDue2031Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_MortgagesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
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Balance Type:
Period Type:

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=pra_PICAMember
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Debt (Narrative) (Details) - USD ($)			1 Months Ended	6 Months Ended		12 Months Ended
Debt (Narrative) (Details) - USD ($)	Jul. 15, 2021	May 05, 2021	Jun. 30, 2021	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2017
Debt Instrument [Line Items]
Repayments of outstanding mortgage loans				$ 16,368,000	$ 751,000
NORCAL Group \| Contribution certificates
Debt Instrument [Line Items]
Principal amount		$ 191,000,000
Debt instrument fair value		175,000,000
Debt instrument, premium		$ 16,000,000
Debt instrument term		10 years
Mortgage loans
Debt Instrument [Line Items]
Debt instrument term						10 years
Repayments of outstanding mortgage loans			$ 15,600,000
Mortgage loans \| Subsequent event
Debt Instrument [Line Items]
Repayments of outstanding mortgage loans	$ 19,700,000
Mortgage loans \| ProAssurance Indemnity
Debt Instrument [Line Items]
Total principal payments						$ 17,900,000
Mortgage loans \| PICA
Debt Instrument [Line Items]
Total principal payments						$ 22,600,000