Fair Value Assets Measured On Recurring Basis Unobservable Input.

No definition available.

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

- Definition

Fixed rate loan maturities range.

+ References

No definition available.

+ Details

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

- Definition

Description of the payment terms of the debt instrument (for example, whether periodic payments include principal and frequency of payments) and discussion about any contingencies associated with the payment.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(3))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

+ Details

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

- Definition

The fair value of financial liabilities, which are not recognized in the financial statements (off-balance sheet) because they fail to meet some other criterion for recognition.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13433-108611

+ Details

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

- Definition

The interest rate applicable to the portion of the carrying amount of long-term borrowings outstanding as of the balance sheet date, including current maturities, which accrues interest at a set, unchanging rate.

+ References

+ Details

Name:	us-gaap_LongTermDebtPercentageBearingFixedInterestRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Total contributions made by each class of partners (i.e., general, limited and preferred partners).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 4.F)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

+ Details

Name:	us-gaap_PartnersCapitalAccountContributions
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_TypeOfArrangementAxis=ccne_SubscriptionAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=ccne_OxerBCPMezzanineFundLPMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=ccne_CommitmentsToInvestMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=ccne_TecumCapitalPartnersIilpMember
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_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Off Balance Sheet Activities - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Feb. 28, 2017	Sep. 30, 2016	Oct. 31, 2015
Fair Value Assets Measured On Recurring Basis Unobservable Input [Line Items]
Commitments to make loans periods	60 days or less
Fixed Interest rate loan				5.75%
Subscription Agreement [Member] \| Oxer [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Line Items]
Capital contributions	$ 3,290
Subscription Agreement [Member] \| Oxer [Member] \| Commitments to Invest [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Line Items]
Off-balance sheet risks, amount, liability					$ 5,000
Subscription Agreement [Member] \| Tecum [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Line Items]
Capital contributions	$ 1,167
Subscription Agreement [Member] \| Tecum [Member] \| Commitments to Invest [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Line Items]
Off-balance sheet risks, amount, liability			$ 3,000
Minimum [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Line Items]
Fixed Interest rate loan	1.00%	1.19%
Fixed rate loan Maturities range	8 months	6 months
Maximum [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Line Items]
Fixed Interest rate loan	18.00%	18.00%
Fixed rate loan Maturities range	30 years	30 years