Reinsurance (Details 2) (USD $)	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Property and Casualty Group
Reinsurance
Ceded premiums written	$ 57,000,000	$ 57,000,000	$ 49,000,000
Life insurance operations \| Erie Family Life Insurance Company (EFL)
Reinsurance
Direct life insurance in force	47,000,000,000	45,000,000,000
Ceded life insurance in force	21,000,000,000	21,000,000,000
Largest amount of in force life insurance ceded to a single reinsurer	10,000,000,000	10,000,000,000
Equipment breakdown, employment practices liability, and identity recovery lines of business \| Property and Casualty Group \| Ceded Credit Risk, Concentrated Credit Risk \| Hartford Steam Boiler Inspection and Insurance Company, an unaffiliated reinsurer \| A.M. Best, A Plus Plus rated
Reinsurance
Percentage of ceded covered insurance risk relating to reinsured portions of certain lines of business through quota share reinsurance agreements (as a percent)	100.00%
Ceded premiums written	$ 24,000,000	$ 21,000,000	$ 17,000,000

Represents the largest amount of life insurance in force ceded to a single reinsurer.

No definition available.

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- Definition

Represents the percentage of the ceded insurance coverage risk related to the reinsured portion of a line of business in a quota share reinsurance agreement.

+ References

No definition available.

+ Details

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- Details

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- Definition

Amount of written premiums ceded to other entities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 17

-Article 12

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 605

-Section 50

-Paragraph 1

-Subparagraph (b),(c)(2)

-URI http://asc.fasb.org/extlink&oid=6486672&loc=d3e27261-158547

+ Details

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- Definition

Amount of life insurance issued and outstanding ceded to other entities. Includes, but not limited to, dividends and adjustments to face value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 17

-Article 12

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 235

-Section S99

-Paragraph 2

-Subparagraph (SX 210.12-17)

-URI http://asc.fasb.org/extlink&oid=34713774&loc=d3e574992-122915

+ Details

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- Definition

Amount before contracts ceded to other entities and contracts assumed by the entity of life insurance issued and outstanding. Includes, but not limited to, dividends and adjustments to face value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 17

-Article 12

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 235

-Section S99

-Paragraph 2

-Subparagraph (SX 210.12-17)

-URI http://asc.fasb.org/extlink&oid=34713774&loc=d3e574992-122915

+ Details

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- Details

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