Additional provision for loan losses.

No definition available.

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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

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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

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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

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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

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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

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

- Definition

Minimum risk rating category of commercial loans.

+ References

No definition available.

+ Details

Name:	ccne_MinimumRiskRatingCategoryOfCommercialLoans
Namespace Prefix:	ccne_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- 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

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Namespace Prefix:	ccne_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- 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

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 7

-Subparagraph d

-Article 9

+ 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=35738203&loc=SL6953676-111524

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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

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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=35738203&loc=SL6953682-111524

+ Details

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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

The increase (decrease) during the reporting period in the value of loans or securitized loans that are held with the intention to sell in the near future.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 21

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3461-108585

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 230

-Section 55

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=34726456&loc=d3e60097-112785

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
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Loans - Additional Information (Detail) (USD $)	12 Months Ended
Loans - Additional Information (Detail) (USD $)	Dec. 31, 2014 Loans	Dec. 31, 2013 Loans	Dec. 31, 2012 Loans	Jan. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net unamortized loan costs and fees	$ 483,000	$ 911,000
Percentage of comprised loan, commercial, industrial and agricultural loans	32.00%	33.00%
Percentage of comprised loan, commercial mortgage loans	26.00%	26.00%
Risk rating to commercial loans	250,000,000
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	37.00%	35.00%
Additional provision for loan losses	319,000	514,000
Minimum period to be considered for loan to have defaulted	90 days
Principal balances forgiven in connection with loan restructuring	0	0
Number of Loans	16	12
Loans modified in a troubled debt restructuring	18,658,000	12,136,000
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	4	3	7
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	3,920,000	1,790,000
Commercial, Industrial, and Agricultural [Member] \| Special Mention [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Increase (Decrease) in loans after reclassification	3,000,000
Commercial, Industrial, and Agricultural [Member] \| Substandard [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Increase (Decrease) in loans after reclassification	10,600,000
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
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	14,738,000	10,346,000
Commercial Mortgages [Member] \| Trouble Debt Restructuring [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans	3
Loans modified in a troubled debt restructuring	4,879,000
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