Represents the percentage at which postretirement benefit expenses are reimbursed to the attorney-in-fact.

No definition available.

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- Definition

Amount of gain (loss) recognized in net periodic benefit (cost) credit of defined benefit plan.

+ References

+ Details

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- Definition

Amount of prior service cost (credit) recognized in net periodic benefit cost (credit) of defined benefit plan.

+ References

+ Details

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- Definition

Amount of contribution received by defined benefit plan from employer which increases plan assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(5)(ii)
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section 50
-Paragraph 6
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-Publisher FASB
-Name Accounting Standards Codification
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-Section 50
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-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920

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-Publisher FASB
-Name Accounting Standards Codification
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-Section 50
-Paragraph 1
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-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

Amount of future annual benefits of participant covered by insurance contract. Includes, but is not limited to, contract issued by employer or its related parties.

+ References

+ Details

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- Definition

Amount of contributions expected to be received by defined benefit plan from employer in fiscal year. Excludes contributions paid by employer in current fiscal year.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 6
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e2709-114920

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- Definition

Amount of expected return (loss) recognized in net periodic benefit (cost) credit, calculated based on expected long-term rate of return and market-related value of plan assets of defined benefit plan.

+ References

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- Definition

Amount of cost recognized for passage of time related to defined benefit plan.

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
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- Definition

Amount of net periodic benefit cost (credit) for defined benefit plan.

+ References

+ Details

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- References

No definition available.

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- Definition

Amount of cost for actuarial present value of benefits attributed to service rendered by employee for defined benefit plan.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

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- Details

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Postretirement Benefits (Details) - Pension plans - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Sep. 30, 2017
Cost of pension plans:
Service cost for benefits earned	$ 7,776	$ 7,050	$ 15,553	$ 14,100
Interest cost on benefits obligation	8,568	8,282	17,137	16,563
Expected return on plan assets	(10,316)	(9,880)	(20,633)	(19,760)
Prior service cost amortization	218	174	436	348
Net actuarial loss amortization	2,325	2,027	4,650	4,055
Pension plan cost	8,571	$ 7,653	$ 17,143	$ 15,306
Erie Insurance Exchange (EIE)
Postretirement Benefits
Postretirement annual benefit expense reimbursed to Indemnity from the Exchange (as a percent)			58.00%
Qualified plan \| Funded plan
Postretirement Benefits
Employer contribution			$ 19,000
Qualified plan \| Funded plan \| Scenario, Forecast [Member]
Postretirement Benefits
Expected additional employer contribution					$ 20,000
Qualified plan \| Funded plan \| Erie Family Life Insurance Company (EFL)
Postretirement Benefits
Contingent liability for amount of nonparticipating annuity contracts the employee pension plan purchased from EFL	$ 20,200		$ 20,200