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Postretirement Benefits - Narrative (Details) - USD ($) $ in Millions | 1 Months Ended | 3 Months Ended
--- | --- | ---
Jan. 31, 2025 | Mar. 31, 2025
Employee pension plan |  |
Postretirement Benefits |  |
Funding target (as a percentage of the funding target liability) |  | 100.00%
Defined benefit plan, plan assets, contributions by employer | $ 39 |
Erie Insurance Exchange | Employee pension plan |  |
Postretirement Benefits |  |
Postretirement annual benefit expense reimbursed from the Exchange and its insurance subsidiaries (as a percent) |  | 61.00%
Erie Insurance Exchange | Supplemental employee retirement plan (SERP) |  |
Postretirement Benefits |  |
Postretirement annual benefit expense reimbursed from the Exchange and its insurance subsidiaries (as a percent) |  | 33.00%

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- Definition Plan assets of a defined benefit plan, as a percentage of the funding target liability as defined by the Pension Protection Act of 2006. + References No definition available. + Details
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- Definition Represents the percentage at which postretirement benefit income and expense are reimbursed to and from, respectively, the attorney-in-fact. + References No definition available. + Details
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- Details
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