Summary of Significant Accounting Policies (Policies)	9 Months Ended
Sep. 30, 2020
Summary of Significant Accounting Policies [Abstract]
Description of Business	Description of Business: Protective Insurance Corporation (the "Company"), based in Carmel, Indiana, is a property-casualty insurer specializing in marketing and underwriting property, liability and workers' compensation coverage for trucking and public transportation fleets, as well as coverage for trucking industry independent contractors. The Company offers a range of products and services, the most significant being commercial automobile and workers' compensation insurance products. The Company operates as one reportable property and casualty insurance segment based on how its operating results are regularly reviewed by its chief operating decision maker when making decisions about how resources are allocated and assessing performance. The term “Insurance Subsidiaries,” as used throughout this document, refers to Protective Insurance Company, Protective Specialty Insurance Company, Sagamore Insurance Company and B&L Insurance, Ltd.
Basis of Presentation	Basis of Presentation: The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with the instructions to Form 10-Q and do not include all of the information and notes required by U.S. generally accepted accounting principles for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for fair presentation have been included. Interim financial statements should be read in conjunction with the Company's annual audited financial statements and other disclosures included in the Company's most recent Annual Report on Form 10-K. Operating results for interim periods are not necessarily indicative of results that may be expected for the year ending December 31, 2020 or any other future period.
Investments	Investments: Carrying amounts for fixed income securities represent fair value and are based on quoted market prices, where available, or broker/dealer quotes for specific securities where quoted market prices are not available. Equity securities are carried at quoted market prices (fair value). Commercial mortgage loans are carried primarily at amortized cost along with an allowance for losses when necessary. These investments represent interests in commercial mortgage loans originated and serviced by a third party of which the Company shares, on a pro-rata basis, in all related cash flows of the underlying mortgage loans. The Company recorded an allowance of $195 on its commercial mortgage loans as of September 30, 2020 in conjunction with the adoption of the new credit losses accounting standard discussed below. The Company accounts for investments in limited partnerships using the equity method of accounting, which requires an investor in a limited partnership to record its proportionate share of the limited partnership's net income. To the extent the limited partnerships include both realized and unrealized investment gains or losses in the determination of net income or loss, then the Company would also recognize, through its condensed consolidated statements of operations, its proportionate share of the investee's unrealized, as well as realized, investment gains or losses within net unrealized gains (losses) on equity securities and limited partnership investments. Short-term and other investments are carried at cost, which approximates their fair values. Fixed income securities are considered to be available-for-sale. The related unrealized net gains or losses (net of applicable tax effects) on fixed income securities are reflected directly in other comprehensive income (loss) within shareholders' equity. Included within available-for-sale fixed income securities are convertible debt securities. A portion of the changes in the fair values of convertible debt securities is reflected as a component of net realized gains (losses) on investments, excluding impairment losses within the condensed consolidated statements of operations. Realized gains and losses on disposals of fixed income securities are recorded on the trade date. Realized gains and losses on fixed income securities are determined by the specific identification of the cost of investments sold and are included in net realized gains (losses) on investments, excluding impairment losses.
Recognition of Revenue and Costs	Recognition of Revenue and Costs: Premiums are earned over the period for which insurance protection is provided. A reserve for unearned premiums is established to reflect amounts applicable to subsequent accounting periods. Commissions to unaffiliated companies and premium taxes applicable to unearned premiums are deferred and expensed as the related premiums are earned. The Company does not defer acquisition costs that are not directly variable with the production of premiums. If it is determined that expected losses and deferred expenses will likely exceed the related unearned premiums, the asset representing deferred policy acquisition costs is reduced and an expense is charged against current operations to reflect any such premium deficiency. In the event that the expected premium deficiency exceeds deferred policy acquisition costs, an additional liability would be recorded with a corresponding expense to current operations for the amount of the excess premium deficiency. Anticipated investment income is considered in determining recoverability of deferred acquisition costs. The Company had no material contract assets, contract liabilities, or deferred contract costs recorded on its condensed consolidated balance sheet at September 30, 2020. The following accounting policies have been updated effective January 1, 2020 to reflect the Company's adoption of Accounting Standards Update ("ASU") No. 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, or ASU 2016-13, as described below.
Investment Impairments	Investment Impairments: For a fixed income security in an unrealized loss position where the Company has the intent to sell the fixed income security, or it is more likely than not that the Company will have to sell the fixed income security before recovery of its amortized cost basis, the decline in value is recorded within impairment losses on investments in the condensed consolidated statements of operations. The new cost basis of the investment is the previous amortized cost basis less the impairment recognized. The new cost basis is not adjusted for any subsequent recoveries in fair value. For a fixed income security that the Company does not intend to sell or in cases where it is more likely than not that the Company will not have to sell the security, the Company separates the credit loss component of the impairment from the amount related to all other factors and reports the credit loss component within net realized gains (losses) on investments, excluding impairment losses in the condensed consolidated statements of operations. The impairment related to all other factors (non-credit factors) is reported in other comprehensive income (loss). The allowance is adjusted for any additional credit losses and subsequent recoveries. Upon recognizing a credit loss, the cost basis is not adjusted. The Company considers the extent to which fair value is below amortized cost in determining whether a credit-related loss exists. The Company also considers the credit quality rating of the security, focusing on those below investment grade, with emphasis on securities downgraded below investment grade. The credit loss is determined by comparing the net present value of projected future cash flows with the amortized cost basis of the fixed income security. The net present value is calculated by discounting the Company's best estimate of projected future cash flows at the appropriate effective interest rate. Additionally, the Company may conclude that a qualitative analysis is sufficient to support its conclusion that the present value of the expected cash flows equals or exceeds a security’s amortized cost. The Company reports investment income due and accrued separately from available-for-sale fixed income securities and has elected not to measure an allowance for credit losses for investment income due and accrued. Investment income due and accrued is written off through net realized gains (losses) on investments, excluding impairment losses at the time the issuer defaults or is expected to default on payments.
Deductible Receivables	Deductible Receivables: Under certain workers’ compensation insurance contracts with deductible features, the Company is obligated to pay the claimant for the full amount of the claim. The Company is subsequently reimbursed by the policyholder for the deductible amount. These amounts are included on a net of allowance basis in the condensed consolidated balance sheets within accounts receivable. The allowance is based upon the Company’s ongoing review of amounts outstanding, changes in policyholder credit standing, and other relevant factors. A probability-of-default methodology, which reflects current and forecasted economic conditions, is used to estimate the allowance for expected credit losses for deductible receivables. As of September 30, 2020, the Company recorded an allowance for expected credit losses of $16,500 ($13,035, net of tax). See Note 10 – Litigation, Commitments and Contingencies for further discussion.
Recently Adopted and Recently Issued Accounting Pronouncements	Recently Adopted Accounting Pronouncements: Effective January 1, 2019, the Company adopted ASU No. 2016-02, Leases (Topic 842), or ASU 2016-02. Under the new guidance, lessees are required to recognize for all leases, with the exception of short-term leases, a lease liability, which is a lessee's obligation to make lease payments arising from a lease, measured on a discounted basis. Concurrently, lessees are required to recognize a right-of-use asset, which is an asset that represents the lessee's right to use, or control the use of, a specified asset for the lease term. The Company's adoption of the new standard did not have any impact on its condensed consolidated statements of operations or cash flows; however, the impact of adopting the new guidance resulted in a right-of-use asset and a lease liability being recorded on the condensed consolidated balance sheet as of September 30, 2020, each of approximately $145, which are included within other assets and accounts payable and other liabilities. In June 2016, the Financial Accounting Standards Board ("FASB") issued ASU 2016-13. ASU 2016-13 introduced a current expected credit loss ("CECL") model for measuring expected credit losses for certain types of financial instruments held at the reporting date requiring significant judgment in application based on historical experience, current conditions and reasonable supportable forecasts, but is not prescriptive about certain aspects of estimating expected losses. The guidance replaced the current incurred loss model for measuring expected credit losses and provided for additional disclosure requirements. Subsequently, the FASB issued additional ASUs on Topic 326 that did not change the core principle of the guidance in ASU 2016-13, but provided clarification and implementation guidance on certain aspects of ASU 2016-13, and had the same effective date and transition requirements as ASU 2016-13. The Company adopted the guidance using a modified retrospective approach as of January 1, 2020 and recognized a cumulative effect adjustment of $15,545 ($12,281, net of tax), to the opening balance of retained earnings. The adjustment was primarily related to estimating credit losses on the Company’s accounts receivable balances, reinsurance recoverable balances and commercial mortgage loans at the date of adoption with $15,000 ($11,850, net of tax) attributed to the ongoing litigation with Personnel Staffing Group ("PSG") discussed in Note 10 - Litigation, Commitments and Contingencies. The updated guidance in ASU 2016-13 also amended the previous other-than-temporary impairment ("OTTI") model for available-for-sale fixed income securities by requiring the recognition of impairments relating to credit losses through an allowance account and limits the amount of credit loss to the difference between a security’s amortized cost basis and its fair value. In addition, the length of time a security has been in an unrealized loss position will no longer impact the determination of whether a credit loss exists. The Company adopted the guidance related to available-for-sale fixed income securities on January 1, 2020 using a prospective transition approach for available-for-sale fixed income securities that were purchased with credit deterioration or had recognized an OTTI write-down prior to the effective date. The effect of the prospective transition approach was to maintain the same amortized cost basis before and after the effective date. In August 2018, the FASB issued ASU No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement, or ASU 2018-13. This update removed the disclosure requirements for the amounts of and the reasons for transfers between Level 1 and Level 2 and disclosure of the policy for timing of transfers between levels. This update also removed disclosure requirements for the valuation processes for Level 3 fair value measurements. Additionally, this update added disclosure requirements for the changes in unrealized gains and losses for recurring Level 3 fair value measurements and quantitative information for certain unobservable inputs in Level 3 fair value measurements. The Company adopted ASU 2018-13 as of January 1, 2020. As the requirements of this guidance are applicable to disclosure only, the adoption of ASU 2018-13 had no material impact on the Company's condensed consolidated financial statements. Recently Issued Accounting Pronouncements: In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes, or ASU 2019-12. Among other items, the amendments in ASU 2019-12 simplify the accounting treatment of tax law changes and year-to-date losses in interim periods. An entity generally recognizes the effects of a change in tax law in the period of enactment; however, there is an exception for tax laws with delayed effective dates. Under current guidance, an entity may not adjust its annual effective tax rate for a tax law change until the period in which the law is effective. This exception was removed under ASU 2019-12, thereby providing that all effects of a tax law change are recognized in the period of enactment, including adjustment of the estimated annual effective tax rate. Regarding year-to-date losses in interim periods, an entity is required to estimate its annual effective tax rate for the full fiscal year at the end of each interim period and use that rate to calculate its income taxes on a year-to-date basis. However, current guidance provides an exception that when a loss in an interim period exceeds the anticipated loss for the year, the income tax benefit is limited to the amount that would be recognized if the year-to-date loss were the anticipated loss for the full year. ASU 2019-12 removes this exception and provides that in this situation, an entity would compute its income tax benefit at each interim period based on its estimated annual effective tax rate. ASU 2019-12 is effective for fiscal years beginning after December 15, 2020, including interim periods within those annual periods. Early adoption is permitted. The Company is currently evaluating the effects the adoption of ASU 2019-12 will have on its condensed consolidated financial statements.

Summary of Significant Accounting Policies (Policies)

9 Months Ended

Sep. 30, 2020

Summary of Significant Accounting Policies [Abstract]

Description of Business: Protective Insurance Corporation (the "Company"), based in Carmel, Indiana, is a property-casualty insurer specializing in marketing and underwriting property, liability and workers' compensation coverage for trucking and public transportation fleets, as well as coverage for trucking industry independent contractors. The Company offers a range of products and services, the most significant being commercial automobile and workers' compensation insurance products. The Company operates as one reportable property and casualty insurance segment based on how its operating results are regularly reviewed by its chief operating decision maker when making decisions about how resources are allocated and assessing performance.

The term “Insurance Subsidiaries,” as used throughout this document, refers to Protective Insurance Company, Protective Specialty Insurance Company, Sagamore Insurance Company and B&L Insurance, Ltd.

Basis of Presentation

Basis of Presentation: The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with the instructions to Form 10-Q and do not include all of the information and notes required by U.S. generally accepted accounting principles for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for fair presentation have been included. Interim financial statements should be read in conjunction with the Company's annual audited financial statements and other disclosures included in the Company's most recent Annual Report on Form 10-K. Operating results for interim periods are not necessarily indicative of results that may be expected for the year ending December 31, 2020 or any other future period.

Investments

Investments: Carrying amounts for fixed income securities represent fair value and are based on quoted market prices, where available, or broker/dealer quotes for specific securities where quoted market prices are not available. Equity securities are carried at quoted market prices (fair value).

Commercial mortgage loans are carried primarily at amortized cost along with an allowance for losses when necessary. These investments represent interests in commercial mortgage loans originated and serviced by a third party of which the Company shares, on a pro-rata basis, in all related cash flows of the underlying mortgage loans. The Company recorded an allowance of $195 on its commercial mortgage loans as of September 30, 2020 in conjunction with the adoption of the new credit losses accounting standard discussed below.

The Company accounts for investments in limited partnerships using the equity method of accounting, which requires an investor in a limited partnership to record its proportionate share of the limited partnership's net income. To the extent the limited partnerships include both realized and unrealized investment gains or losses in the determination of net income or loss, then the Company would also recognize, through its condensed consolidated statements of operations, its proportionate share of the investee's unrealized, as well as realized, investment gains or losses within net unrealized gains (losses) on equity securities and limited partnership investments.

Short-term and other investments are carried at cost, which approximates their fair values.

Fixed income securities are considered to be available-for-sale. The related unrealized net gains or losses (net of applicable tax effects) on fixed income securities are reflected directly in other comprehensive income (loss) within shareholders' equity. Included within available-for-sale fixed income securities are convertible debt securities. A portion of the changes in the fair values of convertible debt securities is reflected as a component of net realized gains (losses) on investments, excluding impairment losses within the condensed consolidated statements of operations. Realized gains and losses on disposals of fixed income securities are recorded on the trade date. Realized gains and losses on fixed income securities are determined by the specific identification of the cost of investments sold and are included in net realized gains (losses) on investments, excluding impairment losses.

Recognition of Revenue and Costs

Recognition of Revenue and Costs: Premiums are earned over the period for which insurance protection is provided. A reserve for unearned premiums is established to reflect amounts applicable to subsequent accounting periods. Commissions to unaffiliated companies and premium taxes applicable to unearned premiums are deferred and expensed as the related premiums are earned. The Company does not defer acquisition costs that are not directly variable with the production of premiums. If it is determined that expected losses and deferred expenses will likely exceed the related unearned premiums, the asset representing deferred policy acquisition costs is reduced and an expense is charged against current operations to reflect any such premium deficiency. In the event that the expected premium deficiency exceeds deferred policy acquisition costs, an additional liability would be recorded with a corresponding expense to current operations for the amount of the excess premium deficiency. Anticipated investment income is considered in determining recoverability of deferred acquisition costs. The Company had no material contract assets, contract liabilities, or deferred contract costs recorded on its condensed consolidated balance sheet at September 30, 2020.

The following accounting policies have been updated effective January 1, 2020 to reflect the Company's adoption of Accounting Standards Update ("ASU") No. 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, or ASU 2016-13, as described below.

Investment Impairments

Investment Impairments: For a fixed income security in an unrealized loss position where the Company has the intent to sell the fixed income security, or it is more likely than not that the Company will have to sell the fixed income security before recovery of its amortized cost basis, the decline in value is recorded within impairment losses on investments in the condensed consolidated statements of operations. The new cost basis of the investment is the previous amortized cost basis less the impairment recognized. The new cost basis is not adjusted for any subsequent recoveries in fair value.

For a fixed income security that the Company does not intend to sell or in cases where it is more likely than not that the Company will not have to sell the security, the Company separates the credit loss component of the impairment from the amount related to all other factors and reports the credit loss component within net realized gains (losses) on investments, excluding impairment losses in the condensed consolidated statements of operations. The impairment related to all other factors (non-credit factors) is reported in other comprehensive income (loss). The allowance is adjusted for any additional credit losses and subsequent recoveries. Upon recognizing a credit loss, the cost basis is not adjusted.

The Company considers the extent to which fair value is below amortized cost in determining whether a credit-related loss exists. The Company also considers the credit quality rating of the security, focusing on those below investment grade, with emphasis on securities downgraded below investment grade. The credit loss is determined by comparing the net present value of projected future cash flows with the amortized cost basis of the fixed income security. The net present value is calculated by discounting the Company's best estimate of projected future cash flows at the appropriate effective interest rate. Additionally, the Company may conclude that a qualitative analysis is sufficient to support its conclusion that the present value of the expected cash flows equals or exceeds a security’s amortized cost.

The Company reports investment income due and accrued separately from available-for-sale fixed income securities and has elected not to measure an allowance for credit losses for investment income due and accrued. Investment income due and accrued is written off through net realized gains (losses) on investments, excluding impairment losses at the time the issuer defaults or is expected to default on payments.

Deductible Receivables

Deductible Receivables: Under certain workers’ compensation insurance contracts with deductible features, the Company is obligated to pay the claimant for the full amount of the claim. The Company is subsequently reimbursed by the policyholder for the deductible amount. These amounts are included on a net of allowance basis in the condensed consolidated balance sheets within accounts receivable. The allowance is based upon the Company’s ongoing review of amounts outstanding, changes in policyholder credit standing, and other relevant factors. A probability-of-default methodology, which reflects current and forecasted economic conditions, is used to estimate the allowance for expected credit losses for deductible receivables. As of September 30, 2020, the Company recorded an allowance for expected credit losses of $16,500 ($13,035, net of tax). See Note 10 – Litigation, Commitments and Contingencies for further discussion.

Recently Adopted and Recently Issued Accounting Pronouncements

Recently Adopted Accounting Pronouncements: Effective January 1, 2019, the Company adopted ASU No. 2016-02, Leases (Topic 842), or ASU 2016-02. Under the new guidance, lessees are required to recognize for all leases, with the exception of short-term leases, a lease liability, which is a lessee's obligation to make lease payments arising from a lease, measured on a discounted basis. Concurrently, lessees are required to recognize a right-of-use asset, which is an asset that represents the lessee's right to use, or control the use of, a specified asset for the lease term. The Company's adoption of the new standard did not have any impact on its condensed consolidated statements of operations or cash flows; however, the impact of adopting the new guidance resulted in a right-of-use asset and a lease liability being recorded on the condensed consolidated balance sheet as of September 30, 2020, each of approximately $145, which are included within other assets and accounts payable and other liabilities.

In June 2016, the Financial Accounting Standards Board ("FASB") issued ASU 2016-13. ASU 2016-13 introduced a current expected credit loss ("CECL") model for measuring expected credit losses for certain types of financial instruments held at the reporting date requiring significant judgment in application based on historical experience, current conditions and reasonable supportable forecasts, but is not prescriptive about certain aspects of estimating expected losses. The guidance replaced the current incurred loss model for measuring expected credit losses and provided for additional disclosure requirements. Subsequently, the FASB issued additional ASUs on Topic 326 that did not change the core principle of the guidance in ASU 2016-13, but provided clarification and implementation guidance on certain aspects of ASU 2016-13, and had the same effective date and transition requirements as ASU 2016-13. The Company adopted the guidance using a modified retrospective approach as of January 1, 2020 and recognized a cumulative effect adjustment of $15,545 ($12,281, net of tax), to the opening balance of retained earnings. The adjustment was primarily related to estimating credit losses on the Company’s accounts receivable balances, reinsurance recoverable balances and commercial mortgage loans at the date of adoption with $15,000 ($11,850, net of tax) attributed to the ongoing litigation with Personnel Staffing Group ("PSG") discussed in Note 10 - Litigation, Commitments and Contingencies.

The updated guidance in ASU 2016-13 also amended the previous other-than-temporary impairment ("OTTI") model for available-for-sale fixed income securities by requiring the recognition of impairments relating to credit losses through an allowance account and limits the amount of credit loss to the difference between a security’s amortized cost basis and its fair value. In addition, the length of time a security has been in an unrealized loss position will no longer impact the determination of whether a credit loss exists. The Company adopted the guidance related to available-for-sale fixed income securities on January 1, 2020 using a prospective transition approach for available-for-sale fixed income securities that were purchased with credit deterioration or had recognized an OTTI write-down prior to the effective date. The effect of the prospective transition approach was to maintain the same amortized cost basis before and after the effective date.

In August 2018, the FASB issued ASU No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement, or ASU 2018-13. This update removed the disclosure requirements for the amounts of and the reasons for transfers between Level 1 and Level 2 and disclosure of the policy for timing of transfers between levels. This update also removed disclosure requirements for the valuation processes for Level 3 fair value measurements. Additionally, this update added disclosure requirements for the changes in unrealized gains and losses for recurring Level 3 fair value measurements and quantitative information for certain unobservable inputs in Level 3 fair value measurements. The Company adopted ASU 2018-13 as of January 1, 2020. As the requirements of this guidance are applicable to disclosure only, the adoption of ASU 2018-13 had no material impact on the Company's condensed consolidated financial statements.

Recently Issued Accounting Pronouncements: In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes, or ASU 2019-12. Among other items, the amendments in ASU 2019-12 simplify the accounting treatment of tax law changes and year-to-date losses in interim periods. An entity generally recognizes the effects of a change in tax law in the period of enactment; however, there is an exception for tax laws with delayed effective dates. Under current guidance, an entity may not adjust its annual effective tax rate for a tax law change until the period in which the law is effective. This exception was removed under ASU 2019-12, thereby providing that all effects of a tax law change are recognized in the period of enactment, including adjustment of the estimated annual effective tax rate. Regarding year-to-date losses in interim periods, an entity is required to estimate its annual effective tax rate for the full fiscal year at the end of each interim period and use that rate to calculate its income taxes on a year-to-date basis. However, current guidance provides an exception that when a loss in an interim period exceeds the anticipated loss for the year, the income tax benefit is limited to the amount that would be recognized if the year-to-date loss were the anticipated loss for the full year. ASU 2019-12 removes this exception and provides that in this situation, an entity would compute its income tax benefit at each interim period based on its estimated annual effective tax rate. ASU 2019-12 is effective for fiscal years beginning after December 15, 2020, including interim periods within those annual periods. Early adoption is permitted. The Company is currently evaluating the effects the adoption of ASU 2019-12 will have on its condensed consolidated financial statements.