Additional provision for loan losses.

No definition available.

Name:	ccne_AdditionalProvisionForLoanLosses
Namespace Prefix:	ccne_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Commercial industrial and agricultural loan amount as maximum percentage of accounts receivable.

+ References

No definition available.

+ Details

Name:	ccne_CommercialIndustrialAndAgriculturalLoanAmountAsMaximumPercentageOfAccountsReceivable
Namespace Prefix:	ccne_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Commercial industrial and agricultural loan amount as maximum percentage of business equipment.

+ References

No definition available.

+ Details

Name:	ccne_CommercialIndustrialAndAgriculturalLoanAmountAsMaximumPercentageOfBusinessEquipment
Namespace Prefix:	ccne_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Commercial industrial and agricultural loan amount as maximum percentage of business inventory.

+ References

No definition available.

+ Details

Name:	ccne_CommercialIndustrialAndAgriculturalLoanAmountAsMaximumPercentageOfBusinessInventory
Namespace Prefix:	ccne_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Commercial mortgage loan amount as maximum percentage of appraised real estate value.

+ References

No definition available.

+ Details

Name:	ccne_CommercialMortgageLoanAmountAsMaximumPercentageOfAppraisedRealEstateValue
Namespace Prefix:	ccne_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Loans segment reclassification adjustments.

+ References

No definition available.

+ Details

Name:	ccne_LoansSegmentReclassificationAdjustments
Namespace Prefix:	ccne_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Minimum period to be considered for loan to have defaulted.

+ References

No definition available.

+ Details

Name:	ccne_MinimumPeriodToBeConsideredForLoanToHaveDefaulted
Namespace Prefix:	ccne_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Modification involving extension of maturity date having loan period.

+ References

No definition available.

+ Details

Name:	ccne_ModificationInvolvingExtensionOfMaturityDateHavingLoanPeriod
Namespace Prefix:	ccne_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Modification involving reduction of stated interest rate having loan period.

+ References

No definition available.

+ Details

Name:	ccne_ModificationInvolvingReductionOfStatedInterestRateHavingLoanPeriod
Namespace Prefix:	ccne_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Outstanding balance of annual loans.

+ References

No definition available.

+ Details

Name:	ccne_OutStandingBalanceOfAnnualLoans
Namespace Prefix:	ccne_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Outstanding balance of semi annual loans.

+ References

No definition available.

+ Details

Name:	ccne_OutstandingBalanceOfSemiAnnualLoans
Namespace Prefix:	ccne_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of commercial industrial and agricultural loans in loan portfolio.

+ References

No definition available.

+ Details

Name:	ccne_PercentageOfCommercialIndustrialAndAgriculturalLoansInLoanPortfolio
Namespace Prefix:	ccne_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage of commercial mortgage loans in loan portfolio.

+ References

No definition available.

+ Details

Name:	ccne_PercentageOfCommercialMortgageLoansInLoanPortfolio
Namespace Prefix:	ccne_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage of consumer loans and credit card products in loan portfolio.

+ References

No definition available.

+ Details

Name:	ccne_PercentageOfConsumerLoansAndCreditCardProductsInLoanPortfolio
Namespace Prefix:	ccne_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage of residential real estate loans in loan portfolio.

+ References

No definition available.

+ Details

Name:	ccne_PercentageOfResidentialRealEstateLoansInLoanPortfolio
Namespace Prefix:	ccne_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Troubled debt restructuring loan principal balance forgiven.

+ References

No definition available.

+ Details

Name:	ccne_TroubledDebtRestructuringLoanPrincipalBalanceForgiven
Namespace Prefix:	ccne_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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_AccountsNotesAndLoansReceivableLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of increase (decrease) of allowance reserve for credit loss.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.7(d))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

Name:	us-gaap_AllowanceForLoanAndLeaseLossesPeriodIncreaseDecrease
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of financing receivables that have been modified by troubled debt restructurings.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=49124121&loc=SL6953676-111524

+ Details

Name:	us-gaap_FinancingReceivableModificationsNumberOfContracts2
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of the outstanding recorded investment related to financing receivables that have been modified by troubled debt restructurings.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=25495931&loc=d3e18845-111554

+ Details

Name:	us-gaap_FinancingReceivableModificationsRecordedInvestment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of investment related to financing receivables modified by troubled debt restructurings within the previous 12 months, for which there was a payment default.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 34
-URI http://asc.fasb.org/extlink&oid=49124121&loc=SL6953682-111524

+ Details

Name:	us-gaap_FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Reflects the amount of the write-down related to a troubled debt restructuring.

+ References

+ Details

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

- Definition

Amount of deferred fees paid by borrowers and unamortized costs incurred to originate loans and leases, unamortized loan commitments and loan syndication fees, and premiums over or discounts from face amounts of loans that are being amortized into income as an adjustment to yield. Excludes amounts for loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6378536&loc=d3e10092-111533

+ Details

Name:	us-gaap_UnamortizedLoanCommitmentAndOriginationFeesAndUnamortizedDiscountsOrPremiums
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	us-gaap_TroubledDebtRestructuringDebtorSubsequentPeriodsAxis=ccne_TroubleDebtRestructuringMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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

Loans - Additional Information (Detail)	12 Months Ended
Loans - Additional Information (Detail)	Dec. 31, 2015 USD ($) Loans	Dec. 31, 2014 USD ($) Loans	Dec. 31, 2013 USD ($) Loans	Dec. 31, 2012 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net unamortized loan (fees) costs	$ (636,000)	$ 483,000
Percentage of comprised loan, commercial, industrial and agricultural loans	30.00%	32.00%
Percentage of comprised loan, commercial mortgage loans	28.00%	26.00%
Percentage of loan-to-value to business equipment	80.00%
Percentage of loan-to-value to accounts receivable	75.00%
Percentage of loan-to-value to business inventory	60.00%
Percentage of loan-to-value to real estate	85.00%
Percentage of residential real estate loan in portfolio	36.00%	37.00%
Additional provision for loan losses	$ 0	$ 319,000
Minimum period to be considered for loan to have defaulted	90 days
Principal balances forgiven in connection with loan restructuring	$ 0	0
Loans modified in a troubled debt restructuring	$ 14,941,000	$ 18,658,000
Number of Loans \| Loans	16	16
Outstanding balance of semi annual loans	Greater than $1 million
Outstanding balance of annual loans	Less than $1 million
Trouble Debt Restructuring [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans \| Loans	1	4	3
Maximum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Maximum percentage of consumer loan and credit card in portfolio	10.00%	10.00%
Reduction in stated interest rate modification having loan range period	15 years
Extension of maturity date modification having loan range period	18 years
Minimum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Reduction in stated interest rate modification having loan range period	4 years
Extension of maturity date modification having loan range period	4 years
Commercial Mortgage Loan One [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Additional provision for loan losses			$ 262,000
Troubled debt restructuring charged off			974,000
Commercial mortgage loan balance amount			1,086,000	$ 1,660,000
Commercial Mortgage Loan Two [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Additional provision for loan losses			615,000
Commercial Mortgage Loan Three [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans modified in a troubled debt restructuring			3,269,000
Additional provision for loan losses			$ 514,000
Commercial, Industrial, and Agricultural [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan portfolio segment reclassification		$ 136,000,000
Loans modified in a troubled debt restructuring	$ 5,040,000	$ 3,920,000
Number of Loans \| Loans	8	7
Commercial, Industrial, and Agricultural [Member] \| Trouble Debt Restructuring [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans modified in a troubled debt restructuring		$ 2,315,000
Number of Loans \| Loans	1	1	1
Additional provision for loan losses		$ 48,000
Commercial Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan portfolio segment reclassification		124,000,000
Loans modified in a troubled debt restructuring	$ 9,901,000	$ 14,738,000
Number of Loans \| Loans	8	9
Commercial Mortgages [Member] \| Trouble Debt Restructuring [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans modified in a troubled debt restructuring		$ 4,879,000
Number of Loans \| Loans	0	3	2
Additional provision for loan losses		$ 271,000
Residential Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan portfolio segment reclassification		12,000,000
Loans modified in a troubled debt restructuring	$ 0	$ 0
Number of Loans \| Loans	0	0
Residential Real Estate [Member] \| Trouble Debt Restructuring [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans \| Loans	0	0	0
Commercial and Industrial [Member] \| Trouble Debt Restructuring [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans modified in a troubled debt restructuring	$ 1,327,000
Number of Loans \| Loans	1
Additional provision for loan losses	$ 0