Employee Benefit Plans - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014 Age Services	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee pretax contribution percentage	100.00%
Employees compensation	50.00%
Corporation's matching contribution and related expenses	$ 620	$ 431	$ 397
Profit sharing contributions	6.00%ccne_ProfitSharingContributions
Compensation percentage in excess of specified amount	5.70%
Excess of compensation	117ccne_ExcessSpecifiedCompensation
Recognized profit sharing expense	1,044ccne_RecognizedProfitSharingExpense	855ccne_RecognizedProfitSharingExpense	783ccne_RecognizedProfitSharingExpense
Obligations of other liabilities	4,316	4,120
Expenses related employee benefit plans	454	541	728
Obligations under survivor benefit plan	987	932
Other liabilities related to survivor benefit plan	55	119	127
Employee retirement health care benefits plan	60
Minimum service period for participation in benefit plan	30
Accumulated benefit obligation	2,744	2,485
Amortized from accumulated other comprehensive income into net periodic benefit cost	173
Weighted average discount rate net periodic benefit cost	4.31%	3.88%	4.29%
Weighted average rate accrued benefit obligations	3.42%	4.31%	3.88%
Expected costs of benefit	5.00%
Percent rate of increase in the health care trend	1.00%
Increase in health care trend rates	273
Increase service and interest costs	21
Percent rate of decrease in the health care trend	1.00%
Decrease in health care trend rates	242
Decrease service and interest costs	$ 19
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee contribution percentage	1.00%
Total contributed by employee percentage	1.00%
Qualifying dependents age group	60
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee contribution percentage	3.00%
Total contributed by employee percentage	4.00%
Qualifying dependents age group	65

Amortized from accumulated other comprehensive income into net periodic benefit cost.

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- Definition

Compensation percentage in excess of specified amount.

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- Definition

Defined benefit plan compensation by employer.

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- Definition

Employee Benefit Plans Contribution By Employee Percentage

+ References

No definition available.

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- Definition

Excess specified compensation.

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No definition available.

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- Definition

Expenses related to supplemental executive retirement plan.

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- Definition

Expenses related to survivor benefit plan.

+ References

No definition available.

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- Definition

Minimum age for participation in benefit plan.

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- Definition

Minimum service period for participation in benefit plan.

+ References

No definition available.

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- Definition

Obligations under survivor benefit plan.

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No definition available.

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- Definition

Percent rate of decrease in the health care trend.

+ References

No definition available.

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Percent rate of increase in the health care trend.

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- Definition

Profit sharing contributions.

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No definition available.

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- Definition

Qualifying dependents age group.

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- Definition

Recognized profit sharing expense.

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- Definition

Weighted average rate accrued benefit obligations.

+ References

No definition available.

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- Definition

For defined benefit pension plans, the actuarial present value of benefits (whether vested or nonvested) attributed by the pension benefit formula to employee service rendered before a specified date and based on employee service and compensation (if applicable) before that date. The accumulated benefit obligation differs from the projected benefit obligation in that it includes no assumption about future compensation levels. For plans with flat-benefit or nonpay-related pension benefit formulas, the accumulated benefit obligation and the projected benefit obligation are the same.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Accumulated Benefit Obligation

-URI http://asc.fasb.org/extlink&oid=6503844

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (e)

-URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e1928-114920

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- Definition

The interest rate used to adjust for the time value of money.

+ References

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- Definition

Amount of effect of a one-percentage-point decrease in the assumed health care cost trend rates on the accumulated postretirement benefit obligation for health care benefits.

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- Definition

Amount of effect of a one-percentage-point decrease in the assumed health care cost trend rates on the aggregate of the service and interest cost components of net periodic postretirement health care benefit costs.

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- Definition

The effect of a one-percentage-point increase in the assumed health care cost trend rates on the accumulated postretirement benefit obligation for health care benefits.

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- Definition

The effect of a one-percentage-point increase in the assumed health care cost trend rates on the aggregate of the service and interest cost components of net periodic postretirement health care benefit costs.

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- Definition

The assumed health care cost trend rate for the next year used to measure the expected cost of benefits covered by the plan (gross eligible charges). This is based upon the annual rate of change in the cost of health care benefits currently provided by the postretirement benefit plan, due to factors other than changes in the composition of the plan population by age and dependency status.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (l)

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-Publisher FASB

-Name Accounting Standards Codification

-Glossary Health Care Cost Trend Rate

-URI http://asc.fasb.org/extlink&oid=6514820

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- Definition

Amount of discretionary contributions made by an employer to a defined contribution plan.

+ References

No definition available.

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- Definition

Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan.

+ References

No definition available.

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- Definition

Maximum percentage of employee gross pay the employee may contribute to a defined contribution plan.

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No definition available.

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- Definition

This represents the entire liability recognized in the balance sheet that is associated with the defined benefit plans.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.15)

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