Significant Accounting Policies	12 Months Ended
Significant Accounting Policies	Dec. 31, 2019
Accounting Policies [Abstract]
Significant Accounting Policies	Significant Accounting Policies Basis of presentation The accompanying financial statements have been prepared in conformity with U.S. generally accepted accounting principles ("GAAP"). Use of estimates The preparation of financial statements in conformity with GAAP requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Recently adopted accounting standards We adopted Accounting Standards Codification ("ASC") 842, "Leases" on January 1, 2019 using the optional transition method, which permits entities to apply the new guidance prospectively with certain practical expedients available. We elected the package of practical expedients which among other things allowed us to carry forward the historical lease classifications. We did not elect the hindsight practical expedient in determining the lease term for existing leases. The adoption of the new standard resulted in the recognition of operating lease assets of $32.7 million and operating lease liabilities of $32.1 million on the Statement of Financial Position at January 1, 2019. The adoption of this standard did not have a material impact on our Statement of Operations and had no impact on our net cash flows. We adopted ASC 606, "Revenue from Contracts with Customers" on January 1, 2018, using the modified retrospective method applied to all contracts. The comparative information for periods preceding January 1, 2018 has not been restated and continues to be reported under the accounting standards in effect for those periods. Under ASC 606, we determined that we have two performance obligations under the subscriber’s agreement. The first performance obligation is providing policy issuance and renewal services. The second performance obligation is acting as the attorney-in-fact on behalf of the Exchange, as well as the service provider for its insurance subsidiaries, with respect to all administrative services. Upon adoption of ASC 606, the management fee earned per the subscriber’s agreement, currently 25% of all direct and affiliated assumed premiums written by the Exchange, is allocated between the two performance obligations. Prior to the adoption of ASC 606, the entire management fee was allocated to the policy issuance and renewal services. Additionally, the expenses we incur and related reimbursements we receive related to the administrative services are presented gross in our Statement of Operations effective January 1, 2018. On January 1, 2018, we established a contract liability of $48.5 million representing the portion of revenue not yet earned related to the administrative services to be provided in subsequent years. We recorded a related deferred tax asset of $10.2 million and a cumulative effect adjustment that reduced retained earnings by $38.3 million. The adoption of ASC 606 changed the presentation of our Statement of Cash Flows, but had no net impact to our cash flows. In 2018, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2018-02, "Income Statement-Reporting Comprehensive Income-Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income", which permits entities to reclassify from accumulated other comprehensive income to retained earnings tax effects stranded in accumulated other comprehensive income as a result of tax reform. We elected to early adopt this guidance effective December 31, 2017 using a portfolio method, which resulted in a decrease of $26.4 million in accumulated other comprehensive income and a corresponding increase in retained earnings. Recently issued accounting standards In August 2018, the FASB issued ASU 2018-15, "Intangibles-Goodwill and Other Internal-Use Software", which aligns the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. ASU 2018-15 is effective for interim and annual reporting periods beginning after December 15, 2019. The amendments under ASU 2018-15 may be applied either retrospectively or prospectively to all implementation costs incurred after the date of adoption and early adoption is permitted. We adopted this guidance on a prospective basis on January 1, 2020 and there was no material impact on our financial statements or disclosures. In June 2016, the FASB issued ASU 2016-13, "Financial Instruments-Credit Losses", which requires financial assets measured at amortized cost to be presented at the net amount expected to be collected through the use of a new forward-looking expected loss model and credit losses related to available-for-sale debt securities to be recognized through an allowance for credit losses. New disclosures are also required upon adoption of this guidance. ASU 2016-13 is effective for interim and annual reporting periods beginning after December 15, 2019. Our financial assets subject to this guidance include our receivable from Erie Insurance Exchange, agent loans, and investments. We do not expect a significant credit loss exposure for our receivable from Erie Insurance Exchange given the financial strength of the Exchange and the lack of any historical credit loss. As the majority of our agent loans are senior secured and have experienced only insignificant default amounts, we have historically not recorded an allowance for credit losses related to our agent loans. Upon adoption of this guidance on January 1, 2020, we established allowances for both the receivable from Erie Insurance Exchange and agent loans and recognized an immaterial cumulative effect adjustment. Our investments are not measured at amortized cost, and therefore do not require the use of a new expected loss model. Our available-for-sale securities will continue to be monitored for credit losses, which will be limited to the amount by which the fair value is below amortized cost and reflected as an allowance for credit losses rather than a reduction of the carrying value of the asset. Cash and cash equivalents – Cash, money market accounts and other short-term, highly liquid investments with a maturity of three months or less at the date of purchase, are considered cash and cash equivalents. Investments Available-for-sale securities – Fixed maturity debt securities and redeemable preferred stock are classified as available-for-sale and reported at fair value with unrealized investment gains and losses, net of income taxes, recognized in other comprehensive income (loss). Available-for-sale securities with a remaining maturity of 12 months or less and any security that we intend to sell as of the reporting date are classified as current assets. Available-for-sale securities are evaluated monthly for other-than-temporary impairment loss. For securities that have experienced a decline in fair value below amortized cost and that we intend to sell, or for which it is more likely than not we will be required to sell the security before recovery of its amortized cost, an other-than-temporary impairment is recognized in earnings. Securities that have experienced a decline in fair value and that we do not intend to sell, and that we will not be required to sell before recovery, are evaluated to determine if the decline in fair value is other-than-temporary. Some factors considered in this evaluation include the extent and duration to which fair value is less than cost, historical operating performance and financial condition of the issuer, short and long-term prospects of the issuer and its industry based upon analysts' recommendations, specific events that occurred affecting the issuer, including a ratings downgrade, near term liquidity position of the issuer and compliance with financial covenants. If a decline is deemed to be other-than-temporary, an assessment is made to determine the amount of the total impairment related to a credit loss and that related to all other factors. Consideration is given to all available information relevant to the collectability of the security in this determination. When the entire amortized cost basis of the security will not be recovered, a credit loss exists. For securities with credit impairments that we did not intend to sell, the credit portion of the loss would be recorded through net income and the non-credit portion of the impairment would be recorded in other comprehensive income. Currently, we have the intent to sell all of our securities that have been determined to have a credit-related impairment. As a result, the entire amount of any impairment is recognized in earnings. Equity securities – Non-redeemable preferred and common stocks are classified as equity securities and reported at fair value with changes in fair value recognized in net realized investment gains (losses). Prior to January 1, 2018, equity securities were classified as available-for-sale and changes in fair value were recognized in other comprehensive income. Securities that we intend to sell as of the reporting date are classified as current assets. Realized gains and losses and investment income – Realized gains and losses on sales of available-for-sale and equity securities are recognized in income based upon the specific identification method and reported as net realized investment gains (losses). Interest income is recognized as earned and includes amortization of premium and accretion of discount. Income is recognized based on the constant effective yield method, which includes periodically updated prepayment assumptions obtained from third party data sources on our prepaying securities. The effective yield for prepaying securities is recalculated on a retrospective basis. Dividend income is recognized at the ex-dividend date. Both interest and dividend income are reported as net investment income. Limited partnership investments – Limited partnership investments primarily include U.S. and foreign private equity investments and are recorded using the equity method of accounting. The partnerships record assets on their balance sheet at fair value. While we perform various procedures in review of the general partners' valuations, we rely on the general partners' financial statements as the best available information to record our share of the partnership unrealized gains and losses resulting from valuation changes. Due to the availability of financial statements provided by the general partner, our share of limited partnership results is generally recorded on a quarter lag within equity in earnings (losses) of limited partnerships. Cash contributions made to and distributions received from the partnerships are recorded in the period in which the transaction occurs. We have made no new limited partnership commitments since 2006, and the balance of limited partnership investments is expected to continue to decrease over time as additional distributions are received. Deferred taxes Deferred tax assets and liabilities are recorded for temporary differences between the tax basis of assets and liabilities and the reported amounts in the financial statements, using the statutory tax rates in effect for the year in which the differences are expected to reverse. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in the results of operations in the period that includes the enactment date under the law. The need for valuation allowances on deferred tax assets are estimated based upon our assessment of the realizability of such amounts. Fixed assets Fixed assets are stated at cost less accumulated depreciation and amortization. Fixed assets are primarily comprised of software, which includes internally used capitalized software and development costs, as well as equipment, buildings and building improvements, and leasehold improvements. Assets in use are depreciated using the straight-line method over the estimated useful life except for leasehold improvements, which are depreciated over the shorter of their economic useful life or the lease term. Software is depreciated over periods ranging from 3-7 years, equipment is depreciated over 3-10 years, and buildings and building improvements are depreciated over 20-45 years. We review long-lived assets for impairment whenever events or changes indicate that the carrying value may not be recoverable. Under these circumstances, if the fair value were less than the carrying amount of the asset, we would recognize a loss for the difference. We capitalize applicable interest charges incurred during the construction period of significant long-term building projects as part of the historical cost of the asset. Other assets Other assets include agent loans, operating lease assets and other long-term prepaid assets. Agent loans are carried at unpaid principal balance with interest recorded in investment income as earned. It is our policy to charge the loans that are in default directly to expense. We do not record an allowance for credit losses on these loans, as the majority of the loans are senior secured and historically have had insignificant default amounts. The determination of whether an arrangement is a lease and the related lease classification is made at inception of a contract. Our leases are classified as operating leases. Effective January 1, 2019, operating lease assets and liabilities are recorded at inception based on the present value of the future minimum lease payments over the lease term at commencement date. When an implicit rate for the lease is not available, we use our incremental borrowing rate based on the information available at commencement date to determine the present value of future payments. Lease terms include options to extend or terminate the lease when it is reasonably certain that we will exercise that option. Most of our lease contracts contain lease and non-lease components. Non-lease components are expensed as incurred. Operating lease assets are included in other assets, and the current and noncurrent portions of the operating lease liabilities are included in accounts payable and accrued expenses and other long-term liabilities, respectively. Agent bonus estimates Our more significant agent bonus plan is based upon an individual agency's property and casualty underwriting profitability and also includes a component for growth in agency property and casualty premiums if the agency's underwriting profitability targets for the book of business are met. The estimate for this agent bonus plan is based upon the performance over 36 months, and is modeled on a monthly basis using actual underwriting results for the two prior years and current year-to-date actual results and forecasted results for the remainder of the year. Our second agent bonus plan is based on an agency's one-year underwriting profitability and uses a similar model but considers actual and forecasted results for a calendar year only. At December 31 of each year, we use actual data available and record an accrual based upon the expected payment amount. These costs are included in cost of operations - policy issuance and renewal services. Recognition of management fee revenue We earn management fees from the Exchange under the subscriber’s agreement for services provided. Pursuant to the subscriber’s agreement, we may retain up to 25% of all direct and affiliated assumed premiums written by the Exchange. The management fee rate is set at least annually by our Board of Directors. The management fee revenue is calculated by multiplying the management fee rate by the direct and affiliated assumed premiums written by the Exchange. Upon adoption of ASC 606 beginning January 1, 2018, we determined we have two performance obligations under the subscriber’s agreement. The first performance obligation is to provide policy issuance and renewal services. The second performance obligation is acting as the attorney-in-fact with respect to the administrative services. Beginning January 1, 2018, our management fee revenue is allocated to these two performance obligations. Prior to the adoption of ASC 606, the entire management fee was allocated to the policy issuance and renewal services. Management fee revenue allocated to the policy issuance and renewal services is recognized at the time of policy issuance or renewal, because it is at the time of policy issuance or renewal when the economic benefit of the service we provide (the substantially completed policy issuance or renewal service) and the control of the promised asset (the executed insurance policy) transfers to the customer. Management fee revenue allocated to the second performance obligation relates to us acting as the attorney-in-fact on behalf of the Exchange, as well as the service provider for its insurance subsidiaries, with respect to the administrative services and is recognized over a four-year period representing the time over which the economic benefit of the services provided (i.e. management of the administrative services) transfers to the customer. Administrative services By virtue of its legal structure as a reciprocal insurer, the Exchange does not have any employees or officers. Therefore, it enters into contractual relationships by and through an attorney-in-fact. Indemnity serves as the attorney-in-fact on behalf of the Exchange with respect to its administrative services in accordance with the subscriber's agreement. The Exchange's insurance subsidiaries also utilize Indemnity for these services in accordance with the service agreements between each of the subsidiaries and Indemnity. Claims handling services include costs incurred in the claims process, including the adjustment, investigation, defense, recording and payment functions. Life insurance management services include costs incurred in the management and processing of life insurance business. Investment management services are related to investment trading activity, accounting and all other functions attributable to the investment of funds. Included in these expenses are allocations of costs for departments that support these administrative functions. Common overhead expenses and certain service department costs incurred by us on behalf of the Exchange and its insurance subsidiaries are reimbursed by the proper entity based upon appropriate utilization statistics (employee count, square footage, vehicle count, project hours, etc.) specifically measured to accomplish proportional allocations, which we believe are reasonable. Prior to the adoption of ASC 606, we recorded the reimbursements we receive for the administrative services expenses as receivables from the Exchange and its subsidiaries with a corresponding reduction to our expenses. Total cash settlements for the Exchange and its subsidiaries were $522.3 million in 2017. Upon adoption of ASC 606 on January 1, 2018, the expenses we incur and related reimbursements we receive for administrative services are presented gross in our Statement of Operations. Reimbursements are settled on a monthly basis. The amounts incurred for these services are reimbursed to Indemnity at cost in accordance with the subscriber's agreement and the service agreements. State insurance regulations require that intercompany service agreements and any material amendments be approved in advance by the state insurance department. Recognition of service agreement revenue Service agreement revenue consists of service charges we collect from policyholders for providing multiple payment plans on policies written by the Exchange. Service charges, which are flat dollar charges for each installment billed beyond the first installment, are recognized as revenue when bills are rendered to the policyholder. Service agreement revenue also includes late payment and policy reinstatement fees, which are also recognized as revenue when bills are rendered to the policyholder.