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Amount of transfers of assets measured on a recurring basis out of Level 2 of the fair value hierarchy into Level 1 which have taken place during the period.

No definition available.

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Amount of transfers of assets measured on a recurring basis out of Level 2 of the fair value hierarchy into Level 3 which have taken place during the period.

No definition available.

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Amount of transfers of assets measured on a recurring basis out of Level 3 of the fair value hierarchy into Level 2 which have taken place during the period.

No definition available.

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-- None. No documentation exists for this element. --

No definition available.

Name:	erie_FairValueTransfersDueToChangesInAvailableMarketObservableInputsAbstract
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Represents the number of securities in the entity's investment portfolio that necessitated reclassification between Level 2 and Level 3 due to trading activity levels.

No definition available.

Name:	erie_NumberOfSecuritiesTransferredFairValueAssetsBetweenLevel2AndLevel3
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Represents the number of securities in the entity's investment portfolio that necessitated reclassification between Level 3 and Level 2 due to trading activity levels.

No definition available.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

No definition available.

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Amount of gain (loss) recognized in the income statement for financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258

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Amount of gain (loss) recognized in other comprehensive income (loss) for financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1a)
-URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258

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Amount of purchases of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)
-URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258

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Amount of sale of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)
-URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258

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Amount of transfer of financial instrument classified as an asset into (out of) level 3 of the fair value hierarchy.

No definition available.

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Fair value of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258

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