Long term purchase commitment costs incurred to date.

No definition available.

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

- Definition

Non cancelable operating leases having remaining term less than one year.

+ References

No definition available.

+ Details

Name:	ccne_NonCancelableOperatingLeasesHavingRemainingTermLessThanOneYear
Namespace Prefix:	ccne_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Rental expense net of rental income.

+ References

No definition available.

+ Details

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

- Definition

Sale leaseback transaction automatic renewals number.

+ References

No definition available.

+ Details

Name:	ccne_SaleLeasebackTransactionAutomaticRenewalsNumber
Namespace Prefix:	ccne_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Sale leaseback transaction lease period.

+ References

No definition available.

+ Details

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

- Definition

Sale leaseback transaction lease renewal period.

+ References

No definition available.

+ Details

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

- Definition

The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

+ Details

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

- Definition

The minimum amount the entity agreed to spend under the long-term purchase commitment.

+ References

No definition available.

+ Details

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

- Details

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

- Definition

The portion of the deferred gain that was recognized in the current period.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

-SubTopic 40

-Section 35

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=35688829&loc=d3e50609-112754

+ Details

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

- Definition

The portion of the gain that will be recorded as income or a reduction in rent expense in future periods less amounts recognized in the current period.

+ References

+ Details

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

- Definition

Amount of cash inflow before closing and deferred financing costs received by a seller-lessee in a sale-leaseback recognized in investing activities.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

-SubTopic 40

-Section 55

-Paragraph 51

-URI http://asc.fasb.org/extlink&oid=28365400&loc=d3e51840-112757

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

-SubTopic 40

-Section 55

-Paragraph 50

-URI http://asc.fasb.org/extlink&oid=28365400&loc=d3e51831-112757

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

-SubTopic 40

-Section 55

-Paragraph 52

-URI http://asc.fasb.org/extlink&oid=28365400&loc=d3e51843-112757

+ Details

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

- Details

Name:	us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=us-gaap_CapitalAdditionsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=ccne_FacilitiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_VehiclesMember
Namespace Prefix:
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Period Type:

Premises and Equipment - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014 Renewal_Terms	Dec. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment [Line Items]
Depreciation on premises and equipment	$ 2,659us-gaap_Depreciation	$ 2,147us-gaap_Depreciation	$ 1,948us-gaap_Depreciation
Rental expense, net of rental income	736ccne_RentalExpenseNetOfRentalIncome	490ccne_RentalExpenseNetOfRentalIncome	351ccne_RentalExpenseNetOfRentalIncome
Sale leaseback transaction, lease term	17 years
Sale leaseback transaction, number of automatic renewals	2
Sale leaseback transaction, two automatic lease renewal, period	5 years
Sale leaseback transaction, sale of property, amount	1,200
Sale leaseback transaction, deferred gain	489
Sale leaseback transaction, gain recognized	19	17	19
Facilities [Member]
Property, Plant and Equipment [Line Items]
Non cancelable operating leases having remaining term less than one year	23
Vehicles [Member]
Property, Plant and Equipment [Line Items]
Non cancelable operating leases having remaining term less than one year	9
Capital Addition Purchase Commitments [Member] \| Clearfield, Pennsylvania [Member]
Property, Plant and Equipment [Line Items]
Contractual commitment to construct / remodel the facility	2,734
Construction-related expenditures	1,740
Capital Addition Purchase Commitments [Member] \| Erie, Pennsylvania [Member]
Property, Plant and Equipment [Line Items]
Contractual commitment to construct / remodel the facility	1,445
Construction-related expenditures	$ 1,360