Loans (Loans Individually And Collectively Evaluated For Impairment) (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
Jun. 30, 2016	Dec. 31, 2015
Financing Receivable, Impaired [Line Items]
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	$ 6,287	$ 4,191
Nonaccrual and accruing restructured loans	129,207	120,975
Nonaccrual and accruing restructured loans, loans individually evaluated for impairment	90,844	80,664
Nonaccrual and accruing restructured loans, loans collectively evaluated for impairment	38,363	40,311
Partial Charge-Offs On Impaired Loans	24,358	28,705
Commercial Financial And Agricultural [Member]
Financing Receivable, Impaired [Line Items]
Nonaccrual and accruing restructured loans	29,823	30,623
Nonaccrual and accruing restructured loans, loans individually evaluated for impairment	29,779	30,595
Nonaccrual and accruing restructured loans, loans collectively evaluated for impairment	44	28
Construction Real Estate, SEPH Commercial Land and Development [Member]
Financing Receivable, Impaired [Line Items]
Nonaccrual and accruing restructured loans	1,700	2,044
Nonaccrual and accruing restructured loans, loans individually evaluated for impairment	1,700	2,044
Construction Real Estate - Remaining Commercial [Member]
Financing Receivable, Impaired [Line Items]
Nonaccrual and accruing restructured loans	4,386	4,676
Nonaccrual and accruing restructured loans, loans individually evaluated for impairment	4,386	4,676
Nonaccrual and accruing restructured loans, loans collectively evaluated for impairment	0	0
Construction Real Estate - Mortgage [Member]
Financing Receivable, Impaired [Line Items]
Nonaccrual and accruing restructured loans	107	117
Nonaccrual and accruing restructured loans, loans individually evaluated for impairment	0	0
Nonaccrual and accruing restructured loans, loans collectively evaluated for impairment	107	117
Construction Real Estate - Installment [Member]
Financing Receivable, Impaired [Line Items]
Nonaccrual and accruing restructured loans	158	178
Nonaccrual and accruing restructured loans, loans individually evaluated for impairment	0	0
Nonaccrual and accruing restructured loans, loans collectively evaluated for impairment	158	178
Residential Real Estate - Commercial [Member]
Financing Receivable, Impaired [Line Items]
Nonaccrual and accruing restructured loans	25,070	25,324
Nonaccrual and accruing restructured loans, loans individually evaluated for impairment	25,070	25,324
Nonaccrual and accruing restructured loans, loans collectively evaluated for impairment	0	0
Residential Real Estate - Mortgage [Member]
Financing Receivable, Impaired [Line Items]
Nonaccrual and accruing restructured loans	31,043	30,521
Nonaccrual and accruing restructured loans, loans individually evaluated for impairment	0	0
Nonaccrual and accruing restructured loans, loans collectively evaluated for impairment	31,043	30,521
Residential Real Estate - HELOC [Member]
Financing Receivable, Impaired [Line Items]
Nonaccrual and accruing restructured loans	2,464	2,622
Nonaccrual and accruing restructured loans, loans individually evaluated for impairment	0	0
Nonaccrual and accruing restructured loans, loans collectively evaluated for impairment	2,464	2,622
Residential Real Estate - Installment [Member]
Financing Receivable, Impaired [Line Items]
Nonaccrual and accruing restructured loans	1,241	2,292
Nonaccrual and accruing restructured loans, loans individually evaluated for impairment	0	0
Nonaccrual and accruing restructured loans, loans collectively evaluated for impairment	1,241	2,292
Commercial Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	275	381
Nonaccrual and accruing restructured loans	29,889	18,025
Nonaccrual and accruing restructured loans, loans individually evaluated for impairment	29,889	18,025
Nonaccrual and accruing restructured loans, loans collectively evaluated for impairment	0	0
Consumer [Member]
Financing Receivable, Impaired [Line Items]
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	20	0
Nonaccrual and accruing restructured loans	3,326	4,553
Nonaccrual and accruing restructured loans, loans individually evaluated for impairment	20
Nonaccrual and accruing restructured loans, loans collectively evaluated for impairment	3,306	4,553
Financing Receivable With No Related Allowance Recorded [Member]
Financing Receivable, Impaired [Line Items]
Partial Charge-Offs On Impaired Loans	$ 20,200	$ 24,200

Financing receivable recorded investment nonaccrual and accruing restructured loans.

No definition available.

Name:	prk_FinancingReceivableRecordedInvestmentNonaccrualAndAccruingRestructuredLoans
Namespace Prefix:	prk_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Financing Receivable Recorded Investment Nonaccrual And Accruing Restructured Loans, Collectively Evaluated for Impairment

+ References

No definition available.

+ Details

Name:	prk_FinancingReceivableRecordedInvestmentNonaccrualAndAccruingRestructuredLoansCollectivelyEvaluatedForImpairment
Namespace Prefix:	prk_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Financing Receivable Recorded Investment Nonaccrual And Accruing Restructured Loans, Individually Evaluated for Impairment

+ References

No definition available.

+ Details

Name:	prk_FinancingReceivableRecordedInvestmentNonaccrualAndAccruingRestructuredLoansIndividuallyEvaluatedForImpairment
Namespace Prefix:	prk_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Partial Charge-Offs On Impaired Loans

+ References

No definition available.

+ Details

Name:	prk_PartialChargeOffsOnImpairedLoans
Namespace Prefix:	prk_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953423-111524

+ Details

Name:	us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- 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.

+ Details

Name:	us-gaap_FinancingReceivableImpairedLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=prk_CommercialFinancialAndAgriculturalMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=prk_ConstructionRealEstateSephCommercialLandAndDevelopmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=prk_ConstructionRealEstateRemainingCommercialMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=prk_ConstructionRealEstateMortgageMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=prk_ConstructionRealEstateInstallmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=prk_ResidentialRealEstateCommercialMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=prk_ResidentialRealEstateMortgageMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=prk_ResidentialRealEstateHomeEquityLineOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=prk_ResidentialRealEstateInstallmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_CommercialRealEstatePortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_ConsumerPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ClassOfFinancingReceivableTypeOfBorrowerAxis=prk_FinancingReceivableWithNoRelatedAllowanceRecordedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: