Document And Entity Information
Due after ten years, Fair Value
Note To Financial Statement Details Textual
Significant Accounting Policies
Note 3 - Investments
Due within one year, Amortized Cost
Note 4 - Fair Value Measurements
Net unrealized gains (losses) on securities available for sale
Note 5 - Policy Acquisition Costs
Due within one year, Fair Value
Note 6 - Intangible Assets and Goodwill
Due after one year through five years, Fair Value
Note 7 - Capitalized Assets
Due after five years through ten years, Fair Value
Note 8 - Leases
Note 9 - Reserve for Losses and Loss Adjustment Expenses
Note 10 - Reinsurance
Insurance, Other [Member]
Note 12 - Stockholders' Equity
Note 13 - Accumulated Other Comprehensive Income
Note 14 - Underwriting Information
Note 16 - Income Taxes
Note 17 - Earnings Per Share
Note 18 - Statutory Financial Information
Schedule II - Condensed Financial Information of Parent Company
Schedule V - Valuation and Qualifying Accounts
Note 3 - Investments - Summary of Available for Sale Investments (Details)
Asset-Backed Securities [Member]
Note 3 - Investments - Security Holdings in an Unrealized Loss Position (Details)
Note 3 - Investments - The Amortized Cost and Fair Value of Fixed Maturity Securities by Contractual Maturity (Details)
Note 3 - Investments - Schedule of Available-for-sale Gross Unrealized Gains or Losses (Details)
Note 3 - Investments - Summary of Net Investment Income (Details)
US States and Political Subdivisions Debt Securities [Member]
Note 3 - Investments - Net Realized and Unrealized Investment Gains and Losses (Details)
Note 4 - Fair Value Measurements - Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details)
Note 5 - Policy Acquisition Costs - Schedule of Policy Acquisition Costs (Details)
Note 6 - Intangible Assets and Goodwill - Schedule of Intangible Assets (Details)
Note 7 - Capitalized Assets - Schedule of Capitalized Assets (Details)
Note 8 - Leases - Supplementary Lease Information (Details)
Note 8 - Leases - Supplementary Lease Information (Details) (Parentheticals)
Note 8 - Leases - Schedule of Future Minimum Lease Payments (Details)
Granted, weighted average grant date fair value (in dollars per share)
Note 9 - Reserve for Losses and Loss Adjustment Expenses - Reconciliation of Changes in Reserve Balance for Losses and Loss Adjustment Expenses (Details)
us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss
12 Months or Longer, Accumulated Loss
us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss
Debt Securities, Available-for-Sale, Unrealized Loss Position, Accumulated Loss
Accumulated Loss
Vested, weighted average grant date fair value (in dollars per share)
Note 9 - Reserve for Losses and Loss Adjustment Expenses - Schedule of Incurred Losses and Allocated Loss Adjustment Expenses on Homeowners' Insurance (Details)
Note 9 - Reserve for Losses and Loss Adjustment Expenses - Schedule of Average Annual Percentage Payout of Incurred Claims on Homeowners' Insurance (Details)
Forfeited, weighted average grant date fair value (in dollars per share)
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue
Non-vested outstanding, weighted average grant date fair value (in dollars per share)
Non-vested outstanding, weighted average grant date fair value (in dollars per share)
Note 9 - Reserve for Losses and Loss Adjustment Expenses - Schedule of Incurred Losses and Allocated Loss Adjustment Expenses on Special Property Insurance (Details)
Note 9 - Reserve for Losses and Loss Adjustment Expenses - Schedule of Average Annual Percentage Payout of Incurred Claims on Special Property Insurance (Details)
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod
Forfeited, shares (in shares)
Note 9 - Reserve for Losses and Loss Adjustment Expenses - Schedule of Incurred Losses and Allocated Loss Adjustment Expenses on Other Insurance (Details)
Equity Instruments Other than Options, Nonvested, Number (in shares)
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number (in shares)
Non-vested, shares (in shares)
Non-vested, shares (in shares)
Note 9 - Reserve for Losses and Loss Adjustment Expenses - Schedule of Average Annual Percentage Payout of Incurred Claims on Other Insurance (Details)
Note 9 - Reserve for Losses and Loss Adjustment Expenses - Reconciliation of Liability for Claims and Claim Adjustments Expenses (Details)
us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss
Less than 12 Months, Accumulated Loss
Vested and Exercisable, options, weighted average remaining contractual term (Year)
Note 10 - Reinsurance - Schedule of Ceded Premiums (Details)
us-gaap_OciBeforeReclassificationsNetOfTaxAttributableToParent
Other comprehensive (loss) income before reclassification, net of tax
US Government Agencies Debt Securities [Member]
us-gaap_ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent
Amounts reclassified from AOCI, net of tax
Note 10 - Reinsurance - Effects of Reinsurance (Details)
Granted, shares (in shares)
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares)
Note 12 - Stockholders' Equity - Common Stock Reserved for Future Issuance (Details)
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod
Vested, shares (in shares)
Note 12 - Stockholders' Equity - Schedule of Stock-based Compensation (Details)
Note 12 - Stockholders' Equity - Summary of Stock Option Activity (Details)
Note 12 - Stockholders' Equity - Summary of RSU Transactions (Details)
Vested and Exercisable, options (in shares)
Note 12 - Stockholders' Equity - Summary of PSU Transactions (Details)
Vested and Exercisable, options, weighted average exercise price (in dollars per share)
Vested and Exercisable, options, aggregate intrinsic value
Other comprehensive income, net:
Note 13 - Accumulated Other Comprehensive Income - Changes in Accumulated Other Comprehensive Income (Loss) (Details)
Note 14 - Underwriting Information - Schedule of Gross Written Premiums (Details)
Note 16 - Income Taxes - Components of Income Tax Expense (Details)
Note 16 - Income Taxes - Deferred Tax Assets and Liabilities (Details)
Note 16 - Income Taxes - Reconciliation of Federal Income Tax Rate (Details)
Note 17 - Earnings Per Share - Earnings Per Share of Common Stock (Details)
Note 18 - Statutory Financial Information - Schedule of Statutory Net Income and Statutory Capital Surplus (Details)
Schedule II - Condensed Financial Information of Parent - Balance Sheets (Details)
us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions
Debt Securities, Available-for-Sale, Unrealized Loss Position, Number of Positions
Schedule II - Condensed Financial Information of Parent - Balance Sheets (Details) (Parentheticals)
plmr_LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidRefundedPriorYears
Prior years
Liability for Unpaid Claims and Claims Adjustment Expense, Claims Paid (Refunded), Prior Years.
Fair value
Debt Securities, Available-for-Sale, Unrealized Loss Position
Schedule II - Condensed Financial Information of Parent Company - Statements of Income (Details)
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period, Intrinsic Value
Schedule II - Condensed Financial Information of Parent Company - Statements of Cash Flows (Details)
Schedule V - Valuation and Qualifying Accounts - Valuation and Qualifying Accounts (Details)
us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest
Balance
Balance
Notes To Financial Statements
Debt Securities, Available-for-Sale, Unrealized Loss Position, Fair Value [Table Text Block]
Notes To Financial Statements [Abstract]
Outstanding, options, weighted average remaining contractual term (Year)
Outstanding, options, aggregate intrinsic value
Less than 12 Months, fair value
12 Months or Longer, fair value
Financial Instruments [Domain]
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice
Outstanding, options, weighted average exercise price (in dollars per share)
Outstanding, options, weighted average exercise price (in dollars per share)
Options canceled, options, weighted average exercise price (in dollars per share)
Financial Instrument [Axis]
Options exercised, options, weighted average exercise price (in dollars per share)
Mortgage and asset-backed securities, Fair Value
Lessee, Operating Leases [Text Block]
Mortgage and asset-backed securities, Amortized Cost
Options, Outstanding, Number (in shares)
Outstanding, options (in shares)
Outstanding, options (in shares)
us-gaap_PolicyTextBlockAbstract
Accounting Policies
Gains on sales of fixed maturity securities
us-gaap_DebtSecuritiesAvailableForSaleRealizedLoss
Losses on sales of fixed maturity securities
us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod
Share-Based Compensation Arrangement by Share-Based Payment Award, Expiration Period (Year)
Number of Shares Authorized (in shares)
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized (in shares)
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year)
us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Rights, Percentage
plmr_PaymentToAcquirePolicyRenewalRights
Purchase of policy renewal rights
Represents the amount of payments to acquire policy renewal rights.
Liabilities [Abstract]
Ceded premiums payable
The increase (decrease) during the reporting period in the aggregate amount of ceded premiums payables.
plmr_PremiumDeficiency
Premium Deficiency
Amount in which expected losses and loss adjustment expenses, unamortized acquisition costs, and policy maintenance costs exceeds the remaining unearned premiums.
plmr_NumberOfStatesCompanyUnderwritesCatastropheInsuranceOnAdmittedBasis
Number Of States Company Underwrites Catastrophe Insurance On Admitted Basis
Represents the number of states in which the company underwrites catastrophe insurance on admitted basis.
Vesting [Axis]
Vesting [Domain]
Share-Based Payment Arrangement, Tranche One [Member]
plmr_IncreaseDecreaseInCededUnearnedPremiums
Ceded unearned premiums
The increase (decrease) during the reporting period in the amount of ceded unearned premiums.
Share-Based Payment Arrangement, Tranche Two [Member]
us-gaap_Assets
Assets
Total assets
plmr_LossAndLossAdjustmentExpenseReserveRedundancy
Loss and Loss Adjustment Expense Reserve Redundancy
Represents the amount of loss and loss adjustment expense reserve redundancy.
Premium taxes
Amount of premium taxes which increases deferred policy acquisition cost.
Plan Name [Axis]
Plan Name [Domain]
Homeowners Insurance Product Line [Member]
Relating to Homeowners Insurance Product Line.
Revenue Recognition, Services, Commissions and Other Income [Policy Text Block]
Disclosure of the company's policy regarding revenue recognition, services, commissions, and other income.
us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions
Share-Based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount
plmr_DeferredPolicyAcquisitionCostsCedingCommissions
Ceding commissions and fronting fees
Amount of Ceding commissions which decreases deferred policy acquisition cost.
us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)
Direct commissions
Amount of deferred policy acquisition cost related to direct commissions.
plmr_NumberOfLargestReinsurers
Number of Largest Reinsurers
Represents the number of largest reinsurers.
Largest Reinsurer Two [Member]
Relating to the largest reinsurer two.
Largest Reinsurer One [Member]
Relating to largest reinsurer one.
Schedule of Reconciliation of Liability for Claims and Claim Adjustment Expenses [Table Text Block]
Tabular disclosure of the reconciliation of liabilities for claims and claim adjustment expenses.
Special Property Product Line [Member]
Relating to the special property product line.
Reinsurance Nonproportional Assumed Property [Member]
Relating to reinsurance nonproportional assumed property.
plmr_PolicyholderBenefitsAndLossesIncurredCeded
Losses, ceded
Amount of policy benefits and loss incurred for policies ceded.
Losses, assumed
Amount of policy benefits and loss incurred for policies assumed.
LAE, direct
Amount, before effect of policies assumed or ceded, loss adjustment expenses paid to policy holders.
Deferred tax assets, net
Losses, net
Amount, after effects of policies assumed or ceded, of expense related to the provision for policy benefits and losses incurred.
Three Largest Reinsurers [Member]
Relating to the three largest reinsurers.
Largest Reinsurer Three [Member]
Relating to the largest reinsurer three.
Losses, direct
Amount, before effect of policies assumed or ceded, claims paid to policy holders.
Ceded Written Premiums Under Fronting and Quota Share Arrangements [Member]
Relating to the ceded written premiums under fronting and quota share arrangements.
plmr_DividendsAndReturnOnCapitalReceivable
Dividends And Return On Capital Receivable
The amount of dividends and return on capital available to the company.
plmr_ThresholdDividendOrDistributionWithoutApprovalOfOregonAndCaliforniaInsuranceCommissioners
Threshold Dividend or Distribution without Approval of Oregon and California Insurance Commissioners
The amount of maximum dividend or distribution that may be made without the prior approval of Oregon and California Insurance Commissioners.
plmr_TrustParValue
Trust, Par Value
Represents the market value of trust accounts held.
Palomar Specialty Reinsurance Company Bermuda Ltd [Member]
Relating to Palomar Specialty Reinsurance Company Bermuda, Ltd.
us-gaap_LossContingencyEstimateOfPossibleLoss
Loss Contingency, Estimate of Possible Loss
plmr_PolicyholderBenefitsAndLossAdjustmentExpensesIncurredCeded
LAE, ceded
Amount of policy benefits and loss adjustment expenses incurred for policies ceded.
LAE, assumed
Amount of policy benefits and loss adjustment expenses incurred for policies assumed.
Dividend Restriction Disclosure [Text Block]
The entire disclosure regarding dividend restrictions.
Prepaid Expense and Other Assets
LAE, net
Amount, after effects of policies assumed or ceded, of expense related to the provision for policy benefits and loss adjustment expenses incurred.
Award Type [Domain]
Award Date [Axis]
Award Date [Domain]
Basis of Presentation and Significant Accounting Policies [Text Block]
Award Type [Axis]
us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization
Accumulated amortization on finite-lived intangibles
Standby Letters of Credit [Member]
Customer relationships
Loss Contingency, Nature [Domain]
Losses and LAE reserve discount
Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from losses and loss-adjustment expense reserve discount.
us-gaap_VariableInterestEntityActivityBetweenVIEAndEntityIncomeOrLossBeforeTax
Variable Interest Entity, Measure of Activity, Income or Loss before Tax
Capitalized Software, cost
Capitalized organizational costs
Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from capitalized organizational costs.
Deferred Intercompany
Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from deferred intercompany.
Loss Contingency Nature [Axis]
State insurance licenses
plmr_MinimumStatutorySolvencyMargin
Minimum Statutory Solvency Margin
The minimum amount of excess of value of assets over that of liabilities.
Statutory Financial Information Disclosure [Text Block]
The entire disclosure for statutory financial information.
plmr_LiquidityRatio
Liquidity Ratio
Represents the amount of current assets divided by the amount of current liabilities in a percentage.
plmr_DividendsReceivedFromSubsidiary
Dividends Received from Subsidiary
Represents the amount of dividend received from subsidiary.
Commitments and Contingencies Disclosure [Text Block]
us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment
Capitalized assets, accumulated depreciation
plmr_DeferredTaxAssetsLiabilitiesNetBeforeValuationAllowance
Net deferred tax asset (liability) before valuation allowance
Amount, before allocation of valuation allowances and after deferred tax liability, of deferred tax asset attributable to deductible differences and carryforwards, without jurisdictional netting.
Property and equipment, net
plmr_DeferredTaxLiabilitiesDeferredAcquisitionCosts
Deferred acquisition costs
Amount of deferred tax liability attributable to taxable temporary differences from deferred acquisition costs.
plmr_EffectiveIncomeTaxRateReconciliationDeductionsDividendsAndTaxExemptInterest
Dividend received deduction and tax-exempt interest, percent
Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to deduction for dividend and tax exempt interest.
Acquisitions
plmr_IncomeTaxReconciliationDividendReceivedDeductionAndTaxExemptInterest
Dividend received deduction and tax-exempt interest
Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to deduction for dividend and tax exempt interest.
Capitalized assets, cost
plmr_IncomeLossFromContinuingOperationsNetOfTaxAttributableToParentBeforeIncomeLossFromSubsidiaries
Loss before equity in net income of subsidiaries
Represents the amount of income from continuing operations, net of tax before income from subsidiaries.
Equity in other comprehensive income (loss) of subsidiaries, net of taxes
Represents other comprehensive income (loss) from investments arising during the period.
us-gaap_Investments
Total investments
Fixed maturity securities available for sale, at fair value (amortized cost: $153,425 in 2024, $51,946 in 2023)
Fixed maturity securities available for sale, at fair value (amortized cost: $973,330 in 2024; $675,130 in 2023)
Debt Securities, Available-for-Sale
Total, Fair Value
Laulima Insurance Company [Member]
Represents the Laulima Insurance Company.
Other investments
Investment in subsidiaries
Investment Income [Table Text Block]
Crop [Member]
Represents crops.
Inland Marine and Other Property [Member]
Represents inland marine and other properties.
Equity method investment
Earthquake Premiums [Member]
Represents earthquake premiums.
Income tax expense
Income tax expense (benefit)
Consolidation, Variable Interest Entity, Policy [Policy Text Block]
Variable Interest Entity, Not Primary Beneficiary [Member]
Gain (Loss) on Securities [Table Text Block]
Variable Interest Entity Disclosure [Text Block]
Net realized and unrealized gains (losses) on investments
Net realized and unrealized losses (gains) on investments
Investments:
us-gaap_DefinedContributionPlanCostRecognized
Defined Contribution Plan, Cost
Restricted cash
Restricted cash
us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay
Cash and cash equivalents
Acquisition expenses, net of ceding commissions and fronting fees
Total Acquisition expenses
Amendment Flag
City Area Code
New Accounting Pronouncements, Policy [Policy Text Block]
Current Fiscal Year End Date
Note receivable from subsidiary
us-gaap_NotesReceivableNet
us-gaap_DebtAndEquitySecuritiesRealizedGainLoss
Net realized investment gains (losses)
Document Fiscal Period Focus
Accrued investment income
Document Fiscal Year Focus
Premium receivable
Document Period End Date
Entity File Number
Entity Emerging Growth Company
Document Type
Entity Small Business
Entity Shell Company
Document Information [Line Items]
Document Information [Table]
Entity Public Float
Entity Filer Category
Entity Current Reporting Status
Entity Voluntary Filers
Entity Well-known Seasoned Issuer
All Trading Arrangements [Member]
Deferred policy acquisition costs, net of ceding commissions and fronting fees
Balance, beginning of year
Balance, end of year
Receivables from subsidiaries
us-gaap_AccountsReceivableNet
us-gaap_ImpairmentOfLongLivedAssetsHeldForUse
Impairment, Long-Lived Asset, Held-for-Use
us-gaap_ConcentrationRiskPercentage1
Concentration Risk, Percentage
Entity Tax Identification Number
Entity Central Index Key
Entity Registrant Name
Gains on sales of equity securities
Product Concentration Risk [Member]
us-gaap_EquitySecuritiesFvNiRealizedLoss
Losses on sales of equity securities
Entity [Domain]
Legal Entity [Axis]
Entity Address, Address Line One
Reinsurer Concentration Risk [Member]
ecd_NonRule10b51ArrTrmntdFlag
Non-Rule 10b5-1 Arrangement Terminated [Flag]
Entity Address, City or Town
ecd_Rule10b51ArrTrmntdFlag
Rule 10b5-1 Arrangement Terminated [Flag]
ecd_Rule10b51ArrAdoptedFlag
Rule 10b5-1 Arrangement Adopted [Flag]
Entity Address, Postal Zip Code
Entity Address, State or Province
Concentration Risk Type [Axis]
ecd_NonRule10b51ArrAdoptedFlag
Non-Rule 10b5-1 Arrangement Adopted [Flag]
Concentration Risk Type [Domain]
Material Terms of Trading Arrangement [Text Block]
ecd_TrdArrIndTitle
Trading Arrangement, Individual Title
ecd_TrdArrIndName
Trading Arrangement, Individual Name
ecd_TrdArrSecuritiesAggAvailAmt
Trading Arrangement, Securities Aggregate Available Amount
Entity Common Stock, Shares Outstanding
Trading Arrangement [Axis]
Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]
ecd_TrdArrAdoptionDate
Trading Arrangement Adoption Date
Revenue Benchmark [Member]
Reinsurance Recoverable for Paid and Unpaid Claims and Claims Adjustments [Member]
Trading Symbol
plmr_ProceedsFromPolicyholdersContributionToSurplus
Policy holder contribution to surplus
Amount of cash inflow from policyholders contribution to surplus.
Concentration Risk Benchmark [Axis]
Concentration Risk Benchmark [Domain]
Reinsurance Recoverable Including Reinsurance Premium Paid [Member]
Policy holder contribution to surplus
Amount of increase (decrease) in additional paid in capital (APIC) resulting from policyholder contribution to surplus.
Local Phone Number
us-gaap_TableTextBlock
Notes Tables
Year 2021 [Member]
Represents year 2021.
plmr_DebtInstrumentBasisSpreadOnVariableRateAdditionalSpreadForDefault
Debt Instrument, Basis Spread on Variable Rate, Additional Spread for Default
Percentage of additional spread for default on basis spread on variable rate of debt instrument.
Chris Uchida [Member]
Represents Chris Uchida.
Mac Armstrong [Member]
Represents Mac Armstrong.
Options [Member]
Represents options.
Jon Christianson [Member]
Represents Jon Christianson.
Revenue Recognition, Premiums Earned, Policy [Policy Text Block]
Reinsurance Accounting Policy [Policy Text Block]
Liability Reserve Estimate, Policy [Policy Text Block]
PSIC [Member]
Represents PSIC.
Interest expense
us-gaap_InterestExpenseDebt
Interest Expense, Debt
us-gaap_FederalHomeLoanBankAdvancesBranchOfFHLBBankAmountOfAdvancesByBranch
Federal Home Loan Bank, Advance, Branch of FHLBank, Amount
Deferred Policy Acquisition Costs, Policy [Policy Text Block]
us-gaap_DisclosureTextBlockAbstract
Notes to Financial Statements
Premiums Receivable, Basis of Accounting, Policy [Policy Text Block]
Subsequent Event [Member]
Goodwill and intangible assets, net
Total intangible assets
Subsequent Event Type [Axis]
Subsequent Event Type [Domain]
Retirement Benefits [Text Block]
Subsequent Events [Text Block]
Fair Value of Financial Instruments, Policy [Policy Text Block]
SEC Schedule, 12-09, Valuation Allowances and Reserves [Domain]
SEC Schedule, 12-09, Valuation Allowance, Deferred Tax Asset [Member]
SEC Schedule, 12-09, Valuation Allowances and Reserves Type [Axis]
us-gaap_FiniteLivedIntangibleAssetUsefulLife
Finite-Lived Intangible Asset, Useful Life (Year)
Earnings Per Share, Policy [Policy Text Block]
us-gaap_Revenues
Total revenues
Other Insurance Lines [Member]
Relating to other insurance lines.
Other Liability Claims [Member]
Relating to other liability claims.
Other underwriting expenses
Income Tax, Policy [Policy Text Block]
Short-Duration Insurance Contract, Prior Accident Years [Member]
Prior accident year in which covered event occurs under terms of short-duration insurance contract.
Internal Use Software, Policy [Policy Text Block]
plmr_DeferredTaxLiabilitiesStateTaxLiability
State deferred tax liability
Amount of deferred tax liability attributable to state taxes.
Other Program Administrators [Member]
Relating to other program administrators.
Property Lines [Member]
Relating to property lines.
Other Liability Occurrence [Member]
Relating to other liability occurrence.
Second Largest Program Administrator [Member]
Relating to second largest program administrator.
Largest Program Administrator [Member]
Relating to the largest program administrator.
us-gaap_ShortdurationInsuranceContractsHistoricalClaimsDurationYearEight
Payout percentage, year 8
Payout percentage, year 9
us-gaap_ShortdurationInsuranceContractsHistoricalClaimsDurationYearTen
Payout percentage, year 10
Share-Based Payment Arrangement [Policy Text Block]
Equity [Text Block]
Payout percentage, year 4
Payout percentage, year 5
Payout percentage, year 6
Payout percentage, year 7
Payout percentage, year 1
Payout percentage, year 2
Payout percentage, year 3
us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill
Impairment of Intangible Assets (Excluding Goodwill)
Short-Duration Insurance Contracts, Schedule of Historical Claims Duration [Table Text Block]
Short-Duration Insurance Contracts, Accident Year 2018 [Member]
Short-Duration Insurance Contracts, Accident Year 2015 [Member]
Short-Duration Insurance Contracts, Accident Year 2016 [Member]
Short-Duration Insurance Contracts, Accident Year 2017 [Member]
us-gaap_DeferredTaxAssetsValuationAllowance
Valuation allowance
Summary of Valuation Allowance [Table Text Block]
Short-Duration Insurance Contracts, Claims Development [Table Text Block]
Short-Duration Insurance Contracts, Accident Year [Axis]
Short-Duration Insurance Contracts, Accident Year [Domain]
us-gaap_DeferredTaxAssetsLiabilitiesNet
Total net deferred tax assets (liabilities)
Impairment or Disposal of Long-Lived Assets, Policy [Policy Text Block]
us-gaap_DeferredTaxAssetsOther
Other
Goodwill and Intangible Assets, Policy [Policy Text Block]
us-gaap_DeferredTaxAssetsGross
Total deferred tax assets
us-gaap_DeferredIncomeTaxLiabilities
Total deferred tax liabilities
CALIFORNIA
us-gaap_PremiumsEarnedNet
Net earned premiums
Unrealized losses on investments
FLORIDA
us-gaap_DeferredTaxAssetsUnrealizedLossesOnAvailableforSaleSecuritiesGross
Deferred compensation
HAWAII
ILLINOIS
Allowance for credit loss on fixed maturity securities
us-gaap_PropertyPlantAndEquipmentUsefulLife
Property, Plant and Equipment, Useful Life (Year)
NEW YORK
Net investment income
OREGON
Ceded premiums written
Ceded Premiums Written
Ceded written premiums
us-gaap_PremiumsWrittenNet
Net written premiums
Employee Stock [Member]
Change in unearned premiums
us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsUnearnedPremiumsReserve
Unearned premiums
Written premiums, direct
TEXAS
Written premiums, assumed
Gross written premiums
Premiums Written, Gross
us-gaap_CashCashEquivalentsAndShortTermInvestments
Cash, Cash Equivalents, and Short-Term Investments
Earned premiums, direct
us-gaap_CededPremiumsEarned
Ceded Premiums Earned
Earned premiums, ceded
WASHINGTON
Earned premiums, assumed
Statutory net income (loss)
Statutory Accounting Practices, Statutory Net Income Amount
Statutory capital and surplus
Statutory Accounting Practices, Statutory Capital and Surplus, Balance
Leasehold Improvements [Member]
Property, Plant and Equipment, Policy [Policy Text Block]
Long-Lived Tangible Asset [Axis]
Segment Reporting Disclosure [Text Block]
Long-Lived Tangible Asset [Domain]
Statutory Accounting Practices Disclosure [Table Text Block]
Statutory Accounting Practice, Jurisdiction [Axis]
Statutory Accounting Practice, Jurisdiction [Domain]
us-gaap_InvestmentIncomeNet
Net investment income
State tax net operating losses
us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents
Cash and cash equivalents at beginning of period
Cash and cash equivalents at end of period
us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations
Cash and cash equivalents and restricted cash
Cash, cash equivalents and restricted cash at beginning of period
Cash, cash equivalents and restricted cash at end of period
Assets [Abstract]
Interest income
us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect
Net increase in cash, cash equivalents and restricted cash
Dividend income
us-gaap_NetCashProvidedByUsedInFinancingActivities
Net cash provided by (used in) financing activities
Executive Officer [Member]
us-gaap_NetCashProvidedByUsedInOperatingActivities
Net cash provided by operating activities
us-gaap_DeferredTaxLiabilitiesOther
Other
us-gaap_NetCashProvidedByUsedInInvestingActivities
Net cash used in investing activities
Losses and loss adjustment expenses
us-gaap_LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidCurrentYear1
Current year
us-gaap_DeferredTaxLiabilitiesDeferredExpenseCapitalizedSoftware
Internally developed software
us-gaap_DeferredTaxLiabilitiesLeasingArrangements
Right-of-use Asset
Current year
Prior years
us-gaap_LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaims1
Total incurred
us-gaap_CostOfGoodsAndServicesSoldAmortization
Cost, Amortization
Investment, Policy [Policy Text Block]
Concentration Risk, Credit Risk, Policy [Policy Text Block]
Schedule of Liability for Unpaid Claims and Claims Adjustment Expense [Table Text Block]
us-gaap_PaymentsForRepurchaseOfCommonStock
Repurchase of common stock
us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense
Proceeds from common stock issued via stock option exercises
Investment expense
plmr_InvestmentIncomeInvestmentIncomeExpense
Amount of income (expenses) related to the generation of investment income.
Net unrealized gains on other investments
Represents the amount of unrealized gain (loss) on other investments during the period.
Title and Position [Domain]
Proceeds from stock offering, net of offering costs
Title and Position [Axis]
Other operating expenses
Total expenses
Proceeds from common stock issued via employee stock purchase plan
Current
Losses and LAE, direct
Losses and LAE, assumed
us-gaap_ReinsuranceEffectOnClaimsAndBenefitsIncurredAmountCeded
Losses and LAE, ceded
Expenses:
us-gaap_ReclassificationFromAociCurrentPeriodTax
Federal income tax (benefit) expense
us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest
Income before income taxes
us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsTax
Federal income tax benefit (expense)
ICFR Auditor Attestation Flag
Comprehensive Income (Loss) Note [Text Block]
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]
State and Local Jurisdiction [Member]
Income Tax Authority, Name [Axis]
Income Tax Authority, Name [Domain]
Internal Revenue Service (IRS) [Member]
Income Tax Jurisdiction [Axis]
Income Tax Jurisdiction [Domain]
Disaggregation of Revenue [Table Text Block]
Domestic Tax Jurisdiction [Member]
Cash and Cash Equivalents, Policy [Policy Text Block]
Cash and Cash Equivalents, Restricted Cash and Cash Equivalents, Policy [Policy Text Block]
us-gaap_UnrecognizedTaxBenefits
Unrecognized Tax Benefits
Accounting Policies [Abstract]
Significant Accounting Policies [Text Block]
us-gaap_OpenTaxYear
Open Tax Year
Related Party [Member]
Condensed Financial Information of Parent Company Only Disclosure [Text Block]
Auditor Name
Auditor Firm ID
Short-Duration Insurance Contract, Accident Year 2023 [Member]
Auditor Location
Common Share equivalents (in shares)
us-gaap_TaxCreditCarryforwardAmount
Tax Credit Carryforward, Amount
Diluted (in shares)
Diluted (in shares)
us-gaap_OperatingLossCarryforwards
Operating Loss Carryforwards
Statement of Financial Position [Abstract]
us-gaap_ReinsuranceRetentionAmountRetainedPerEvent
Reinsurance, Amount Retained, Per Event
Diluted earnings per share (in dollars per share)
Basic (in shares)
Per Share Data:
Other, percent
us-gaap_EffectiveIncomeTaxRateContinuingOperations
Income tax expense (benefit), percent
Business Acquisition [Axis]
Basic earnings per share (in dollars per share)
Business Acquisition, Acquiree [Domain]
Net (payments on) proceeds from line of credit
Weighted-average common shares outstanding:
us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance
Valuation allowance, percent
us-gaap_DebtSecuritiesAvailableForSaleAllowanceForCreditLoss
Debt Securities, Available-for-Sale, Allowance for Credit Loss
Available-for-Sale, Allowance for Credit Loss
Statement of Cash Flows [Abstract]
Statement of Stockholders' Equity [Abstract]
Change in allowance for credit losses
Short-Duration Insurance Contract, Accident Year 2022 [Member]
Investments Classified by Contractual Maturity Date [Table Text Block]
Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]
Schedule of Deferred Tax Assets and Liabilities [Table Text Block]
Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]
Unrealized Gain (Loss) on Investments [Table Text Block]
Stock-based compensation, percent
Schedule of Intangible Assets and Goodwill [Table Text Block]
Schedule of Available-for-Sale Securities Reconciliation [Table Text Block]
Meals & entertainment, penalties & parking, percent
us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes
State tax expense
us-gaap_IncomeTaxReconciliationOtherAdjustments
Other
Financing activities
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]
Expense computed at federal tax rate, percent
us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance
Valuation allowance
us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired
Acquisitions, net of cash acquired
us-gaap_PaymentsToAcquireEquityMethodInvestments
Purchase of equity method investment
Class of Stock [Axis]
Fixed maturities securities, amortized cost
us-gaap_IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost
Stock-based compensation
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]
Meals & entertainment, penalties & parking
us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes
State tax expense
Short-Duration Insurance Contract, Accident Year 2020 [Member]
Expense computed at federal tax rate
Income Tax Disclosure [Text Block]
us-gaap_BusinessCombinationConsiderationTransferred1
Business Combination, Consideration Transferred
Share-Based Payment Arrangement, Activity [Table Text Block]
us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired
Business Acquisition, Percentage of Voting Interests Acquired
Sales of equity securities
Sales and maturities of fixed maturity securities
us-gaap_ProceedsFromSaleOfAvailableForSaleSecuritiesDebt
Proceeds from Sale of Debt Securities, Available-for-Sale
Share-Based Payment Arrangement, Cost by Plan [Table Text Block]
Schedule of Nonvested Performance-Based Units Activity [Table Text Block]
Schedule of Nonvested Restricted Stock Units Activity [Table Text Block]
us-gaap_PaymentsForAdvanceToAffiliate
Investments in limited partnerships
Equity securities, at fair value: (cost: $1,725 in 2024, $1,725 in 2023)
Equity securities, at fair value (cost: $32,987 in 2024; $43,003 in 2023)
us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt
Purchases of fixed maturity securities
us-gaap_PaymentsToAcquireMarketableSecurities
Purchases of equity securities
Goodwill and Intangible Assets Disclosure [Text Block]
Revolving Credit Facility [Member]
Credit Facility [Axis]
Credit Facility [Domain]
us-gaap_PaymentsForSoftware
Capitalized software costs
us-gaap_PaymentsToAcquirePropertyPlantAndEquipment
Purchases of property and equipment
Fixed maturities
us-gaap_DebtSecuritiesUnrealizedGainLoss
Cash paid for income taxes
Net unrealized gains (losses) on equity securities
us-gaap_DebtAndEquitySecuritiesGainLoss
Net realized and unrealized gains (losses) on investments
Supplementary cash flow information:
Customer Relationships [Member]
Finite-Lived Intangible Assets by Major Class [Axis]
Finite-Lived Intangible Assets, Major Class Name [Domain]
Equity in net income of subsidiaries
Equity in undistributed earnings of subsidiaries
Net income
Net income
Restricted Stock Units (RSUs) [Member]
Performance Shares [Member]
Share-Based Payment Arrangement, Option [Member]
Short-Duration Insurance Contract, Accident Year 2021 [Member]
Investing activities
Earnings Per Share [Text Block]
BERMUDA
Accounts payable and other accrued liabilities
us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities
Reserve for losses and loss adjustment expense, net of reinsurance
Funds held under reinsurance treaty
Ceded Credit Risk [Table Text Block]
Stock-Based Compensation Expense
Reinsurance [Text Block]
Effects of Reinsurance [Table Text Block]
Unearned premiums
us-gaap_IncreaseDecreaseInUnearnedPremiums
Reserve for losses and loss adjustment expenses
us-gaap_IncreaseDecreaseInLiabilityForClaimsAndClaimsAdjustmentExpenseReserve
us-gaap_ComprehensiveIncomeNetOfTax
Total comprehensive income
us-gaap_TreasuryStockSharesAcquired
Treasury Stock, Shares, Acquired (in shares)
Income taxes payable
us-gaap_IncreaseDecreaseInIncomeTaxes
us-gaap_SharesOutstanding
Balance (in shares)
Balance (in shares)
Common Stock, Shares, Outstanding (in shares)
Common Stock, Shares, Outstanding (in shares)
Preferred Stock, Shares Outstanding (in shares)
Preferred Stock, Shares Outstanding (in shares)
us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Debt Instrument, Basis Spread on Variable Rate
us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets
Prepaid expenses and other assets
Weighted-average discount rate on operating leases
us-gaap_OperatingLeaseCost
Operating Lease, Cost
Lease, Cost [Table Text Block]
Weighted-average remaining lease term on operating leases (years) (Year)
us-gaap_DebtInstrumentFaceAmount
Debt Instrument, Face Amount
us-gaap_CapitalizedComputerSoftwareAccumulatedAmortization
Capitalized Software, accumulated amortization
SEC Schedule, 12-09, Allowance, Uncollectible Premium Receivable [Member]
Variable Rate [Domain]
Capitalized Software, net
us-gaap_CapitalizedComputerSoftwareAmortization1
Capitalized Computer Software, Amortization
Variable Rate [Axis]
Stock-based compensation
us-gaap_StockRepurchasedAndRetiredDuringPeriodValue
Repurchases of common stock
us-gaap_StockRepurchasedAndRetiredDuringPeriodShares
Repurchases of common stock (in shares)
us-gaap_IncreaseDecreaseInPremiumsReceivable
Premium receivable
us-gaap_IncreaseDecreaseInFundsHeldUnderReinsuranceAgreements
Funds held under reinsurance treaty
us-gaap_IncreaseDecreaseInReinsuranceRecoverable
Reinsurance recoverables
us-gaap_IncreaseDecreaseInAccruedInvestmentIncomeReceivable
Accrued investment income
us-gaap_IncreaseDecreaseInDeferredPolicyAcquisitionCosts
Deferred policy acquisition costs
Issuance of common stock via employee stock purchase plan (in shares)
Stock Issued During Period, Shares, Employee Stock Purchase Plans (in shares)
us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised
Options exercised, options (in shares)
Issuance of common stock via employee stock purchase plan
us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Line of Credit Facility, Maximum Borrowing Capacity
us-gaap_LineOfCreditFacilityCommitmentFeeAmount
Line of Credit Facility, Commitment Fee Amount
us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage
Related and Nonrelated Parties [Axis]
Related and Nonrelated Parties [Domain]
Issuance of common stock via equity incentive plan (in shares)
Issuance of common stock via equity incentive plan
Secured Overnight Financing Rate (SOFR) [Member]
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod
Options canceled, options (in shares)
Line of Credit Facility, Lender [Domain]
Issuance of common stock in stock offering, net of offering costs (in shares)
Lender Name [Axis]
us-gaap_LiabilitiesAndStockholdersEquity
Total liabilities and stockholders' equity
Short-Duration Insurance Contract, Accident Year 2024 [Member]
Issuance of common stock in stock offering, net of offering costs
Retained earnings
Accumulated other comprehensive income (loss)
Debt Disclosure [Text Block]
Changes in operating assets and liabilities:
us-gaap_AdjustmentsNoncashItemsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities
Changes in operating assets and liabilities:
Operating lease liabilities
Total operating lease liability
Deferred income tax expense
Operating Lease, Liability, Statement of Financial Position [Extensible Enumeration]
Operating lease ROU assets
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]
us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue
Total future minimum lease payments
us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount
Less: imputed interest
Deferred
us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree
2027
us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour
2028
us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive
2029
Thereafter
Net Investment in Lease, before Allowance for Credit Loss
us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths
2025
us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo
2026
Lessee, Operating Lease, Liability, to be Paid, Maturity [Table Text Block]
Stock-based compensation expense
Short-Duration Insurance Contract, Accident Year 2019 [Member]
Amortization of premium on fixed maturity securities
us-gaap_AssetsFairValueDisclosure
Total assets
Equity Securities, Cost
Depreciation and amortization expense
us-gaap_DebtAndEquitySecuritiesUnrealizedGainLoss
Net increase (decrease)
Common stock, $0.0001 par value, 500,000,000 shares authorized, 26,529,402 and 24,772,987 shares issued and outstanding as of December 31, 2024 and December 31, 2023, respectively
Adjustments to reconcile net income to net cash provided by operating activities:
Measurement Frequency [Axis]
Measurement Frequency [Domain]
Fair Value, Recurring [Member]
Common Stock, Shares Authorized (in shares)
Common Stock, Shares Authorized (in shares)
Common Stock, Shares, Issued (in shares)
Common Stock, Shares, Issued (in shares)
Common Stock, Par Value (in dollars per share)
Common Stock, Par or Stated Value Per Share (in dollars per share)
us-gaap_CommonStockCapitalSharesReservedForFutureIssuance
Total (in shares)
Statistical Measurement [Domain]
Operating cash outflows from operating leases
Maximum [Member]
Minimum [Member]
Product and Service [Axis]
Product and Service [Domain]
Statistical Measurement [Axis]
us-gaap_PaymentsForLossesAndLossAdjustmentExpense
Total payments
Preferred stock, $0.0001 par value, 5,000,000 shares authorized as of December 31, 2024 and December 31, 2023, 0 shares issued and outstanding as of December 31, 2024 and December 31, 2023
Preferred Stock, Shares Issued (in shares)
Preferred Stock, Shares Issued (in shares)
Cash paid for interest
Property, Plant and Equipment Disclosure [Text Block]
Geographical [Axis]
Property, Plant and Equipment [Table Text Block]
Geographical [Domain]
Preferred Stock, Shares Authorized (in shares)
Preferred Stock, Shares Authorized (in shares)
us-gaap_FairValueInvestmentsEntitiesThatCalculateNetAssetValuePerShareUnfundedCommittments
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments
Preferred Stock, Par Value (in dollars per share)
Preferred Stock, Par or Stated Value Per Share (in dollars per share)
Fair Value, Inputs, Level 3 [Member]
Fair Value Hierarchy and NAV [Domain]
Customer [Axis]
Customer [Domain]
Fair Value, Inputs, Level 1 [Member]
Fair Value, Inputs, Level 2 [Member]
Catastrophe [Member]
Fair Value Hierarchy and NAV [Axis]
Dividend received from subsidiary
us-gaap_ProceedsFromDividendsReceived
Proceeds from Dividends Received
Catastrophic Event [Domain]
Amortization of net policy acquisition costs
Amortization of net policy acquisition costs
Hurricane [Member]
Earthquake [Member]
Catastrophic Event [Axis]
Operating activities
Period costs
Reinsurer, Name [Axis]
Deferred Policy Acquisition Costs [Table Text Block]
Reinsurer, Name [Domain]
us-gaap_DeferredPolicyAcquisitionCostsAdditions
Total net additions
Statement [Line Items]
Deferred Policy Acquisition Costs [Text Block]
Add: Reinsurance recoverables on unpaid losses and loss adjustment expenses at end of period
Reinsurance recoverable on unpaid losses and loss adjustment expenses
us-gaap_ReinsuranceRecoverablesOnPaidAndUnpaidLosses
Reinsurance Recoverable for Paid and Unpaid Claims and Claims Adjustments
Ceded unearned premiums
Prepaid Reinsurance Premiums
Net unrealized losses on equity method investment
Amount of unrealized gain (loss) on investment in equity method security measured at fair value with change in fair value recognized in net income (FV-NI).
Additional paid-in capital
Additional Paid in Capital, Common Stock
Reinsurance recoverable on paid losses and loss adjustment expenses
AOCI Attributable to Parent [Member]
Stockholders' equity:
Ceded premium payable
Fair Value Disclosures [Text Block]
us-gaap_Liabilities
Liabilities
Total liabilities
Counterparty Name [Axis]
Counterparty Name [Domain]
Parent Company [Member]
Subsidiaries [Member]
Consolidated Entities [Axis]
Income taxes payable
Consolidated Entities [Domain]
Federal income tax payable
Payables to subsidiaries
Commission and other income
The amount of commission and other revenue earned during period.
Accounts Payable and Other Accrued Liabilities
Securities on Deposit With State Regulatory Authorities [Member]
Represents securities on deposit with state regulatory authorities.
Condensed Cash Flow Statement [Table Text Block]
Condensed Balance Sheet [Table Text Block]
Change in securities receivable or payable, net
The net cash outflow or inflow from securities during the period, which are classified as investing activities.
Condensed Income Statement [Table Text Block]
plmr_DebtAndEquitySecuritiesRealizedGain
Total realized gains
Amount of realized gain on investment in debt and equity securities.
Cash, cash equivalents, and restricted cash
plmr_CashCashEquivalentsAndRestrictedCashFairValueDisclosure
Fair value portion of cash, cash equivalents and restricted cash.
plmr_DebtAndEquitySecuritiesRealizedLoss
Total realized losses
Amount of realized loss on investment in debt and equity securities.
Special Revenue Excluding Asset Backed Securities [Member]
Represents special revenue excluding asset backed securities.
Corporate Debt Securities and Other Debt Obligations [Member]
Represents corporate debt securities and other debt obligations.
Reserve for Losses and Loss Adjustment Expenses [Text Block]
The entire disclosure of reserve for losses and loss adjustment expenses.
Insurance contracts, incurred but not reported liabilities
Insurance contracts, number of claims
Insurance contracts, claim expense
Retained Earnings [Member]
plmr_ReinsurancePolicyExcessOfLossProtectionAmount
Reinsurance Policy, Excess of Loss Protection Amount
Excess of loss protection amount of reinsurance policy.
Insurance contracts, claims paid and allocated claim adjustment expense
Deferred Rent Credit
Alternate Base Rate [Member]
Represents alternate base rate.
Additional Paid-in Capital [Member]
Hawaii Hurricane [Member]
Represents Hawaii Hurricane.
Common Stock [Member]
plmr_CatastropheBondFaceValue
Catastrophe Bond, Face Value
Fair value amount of catastrophe bond.
U.S. Hurricane [Member]
Represents U.S. hurricane.
Equity Components [Axis]
Equity Component [Domain]
plmr_FederalHomeLoanBankAdvancesGeneralDebtObligationsMaximumAmountAvailableAsPercentageOfStatutoryAdmittedAssets
Federal Home Loan Bank, Advances, General Debt Obligations, Maximum Amount Available as Percentage of Statutory Admitted Assets
Amount of maximum advances or credit lines available from the Federal Home Loan Bank (FHLB) as percentage of statutory admitted assets,
us-gaap_LongTermDebt
Long-Term Debt
Borrowings from credit agreements
Casualty [Member]
Represents casualty.
Fronting Premium [Member]
Represents fronting premium.
Inland Marine [Member]
Represents inland marine.
Palomar Excess And Surplus Insurance Company [Member]
Represents Palomar Excess And Surplus Insurance Company.
Equity Incentive Plan 2019 [Member]
Represents Equity Incentive Plan 2019.
us-gaap_LineOfCredit
Long-Term Line of Credit
Percentage of Gross Written Premiums
Percentage of Gross Written Premiums
Represents percentage of gross written premiums.
Palomar Specialty Insurance Company [Member]
Represents Palomar Specialty Insurance Company.
Other States [Member]
Represents other states.
plmr_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardServicePeriod
Share-based Compensation Arrangement by Share-based Payment Award, Award Service Period (Year)
Duration of award service period under share-based compensation arrangement.
plmr_SharebasedCompensationArrangementBySharebasedPaymentAwardSharesAvailableForIssuanceAuthorizedAnnualIncreaseMaximum
Share-based Compensation Arrangement by Share-based Payment Award, Shares Available for Issuance, Authorized Annual Increase, Maximum (in shares)
Represents maximum authorized annual increase of shares under share-based compensation arrangement for shares available for grant.
plmr_PredeterminedPerformanceAchievementPercentage
Predetermined Performance Achievement, Percentage
Represents predetermined performance achievement as a percentage.
Share Based Payment Arrangement Tranche One First Anniversary [Member]
Represents vesting on first anniversary.
plmr_ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageNumberOfAdditionalSharesAvailableForGrant
Share Based Compensation Arrangement By Share Based Payment Award Percentage, Number of Additional Shares Available for Grant
Represents the increase in the number of shares available for grant under the plan as a percentage of common stock issued and outstanding as of the immediately preceding fiscal year end date.
plmr_NumberOfDaysAchievementOfMilestoneStockPrice
Number of Days, Achievement of Milestone Stock Price
Represents number of dates for achievement of milestone stock price.
Employee Stock Purchase Plan 2019 [Member]
Represents employee stock purchase plan 2019.
Office Equipment [Member]
Schedule of Capital Reserved for Future Issuance [Table Text Block]
The tabular disclosure of common stock reserved for future issuance.
Document Annual Report
plmr_ThresholdDividendOrDistributionWithoutApprovalOfArizonaInsuranceCommissioner
Threshold Dividend or Distribution without Approval of Arizona Insurance Commissioner
The amount of maximum dividend or distribution that may be made without the prior approval of the Arizona Insurance Commissioner.
Angela Grant [Member]
Represents Angela Grant.
First Indemnity of America Insurance Company [Member]
Identification of the acquiree in a material business combination (or series of individually immaterial business combinations), which may include the name or other type of identification of the acquiree.
Computer Equipment [Member]
Entity Incorporation, State or Country Code
Document Transition Report
Document Financial Statement Error Correction [Flag]
Entity Interactive Data Current
Vesting Upon Completion of Requisite Service Period [Member]
Vesting schedule of award under share-based payment arrangement.
Security Exchange Name
Title of 12(b) Security
All Individuals [Member]
us-gaap_ValuationAllowancesAndReservesBalance
Valuation Allowance
Valuation Allowance
Valuation allowance, additions
Valuation allowance, deductions
Individual [Axis]
Lease Liability
Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences for lease liabilities.
Unearned premiums
Unearned Premiums
SEC Schedule, 12-09, Schedule of Valuation and Qualifying Accounts Disclosure [Text Block]
Reserve for losses and loss adjustment expenses gross of reinsurance recoverables on unpaid losses and loss adjustment expenses at end of period
Reserve for losses and loss adjustment expenses
Statement [Table]
us-gaap_InterestExpenseLoansFromOtherFederalHomeLoanBanks
Interest Expense, Loans from Other Federal Home Loan Banks
Income Statement [Abstract]
Other comprehensive income (loss), net of tax
Other comprehensive (loss) income
Reserve for losses and loss adjustment expense, net of reinsurance
us-gaap_LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet
Reserve for losses and loss adjustment expense, net of reinsurance recoverables at beginning of period
Reserve for losses and loss adjustment expense net of reinsurance recoverables at end of period
Other comprehensive (loss) income before reclassification
us-gaap_ReclassificationFromAociCurrentPeriodBeforeTaxAttributableToParent
Amounts reclassified from AOCI
us-gaap_StockholdersEquity
Equity, Attributable to Parent
Total stockholders' equity
us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
Available-for-sale, Accumulated Gross Unrealized Loss
Available-for-sale, Accumulated Gross Unrealized Gain
Available-for-Sale, Amortized Cost
Amortized Cost
Due after one year through five years, Amortized Cost
Due after five years through ten years, Amortized Cost
Due after ten years, Amortized Cost
ecd_TradingArrByIndTable
Trading Arrangements, by Individual [Table]