Deposits (Details) - USD ($) $ in Thousands	9 Months Ended
Sep. 30, 2021	Dec. 31, 2020
Banking and Thrift, Interest [Abstract]
Non-interest bearing demand deposits	$ 774,851	$ 627,114
Interest bearing demand deposits	1,031,488	951,903
Savings	2,350,266	2,126,183
Certificates of deposit	437,023	476,544
Total deposits	$ 4,593,628	$ 4,181,744
Percentage Change, Non-interest bearing demand deposits	23.60%
Percentage Change, Interest bearing demand deposits	8.40%
Percentage Change, Savings	10.50%
Percentage Change, Certificates of deposit	(8.30%)
Percentage Change	9.80%

Certificate of Deposit Increase (Decrease), Percentage

No definition available.

Name:	ccne_CertificateOfDepositIncreaseDecreasePercentage
Namespace Prefix:	ccne_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Deposits Increase (Decrease), Percentage.

+ References

No definition available.

+ Details

Name:	ccne_DepositsIncreaseDecreasePercentage
Namespace Prefix:	ccne_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Interest Bearing Checking Deposit Increase (Decrease), Percentage.

+ References

No definition available.

+ Details

Name:	ccne_InterestBearingCheckingDepositIncreaseDecreasePercentage
Namespace Prefix:	ccne_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Non Interest Bearing Checking Deposit Increase (Decrease), Percentage.

+ References

No definition available.

+ Details

Name:	ccne_NonInterestBearingCheckingDepositIncreaseDecreasePercentage
Namespace Prefix:	ccne_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Saving Accounts Deposit Increase (Decrease), Percentage

+ References

No definition available.

+ Details

Name:	ccne_SavingAccountsDepositIncreaseDecreasePercentage
Namespace Prefix:	ccne_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- References

No definition available.

+ Details

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

- Definition

The aggregate of all deposit liabilities held by the entity, including foreign and domestic, interest and noninterest bearing; may include demand deposits, saving deposits, Negotiable Order of Withdrawal (NOW) and time deposits among others.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.12)
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

+ Details

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

- Definition

Amount of interest-bearing domestic certificate of deposit liabilities.

+ References

+ Details

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

- Definition

Amount of interest-bearing domestic checking deposit liabilities.

+ References

+ Details

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

- Definition

Amount of interest-bearing domestic savings deposit liabilities. Saving deposits bear interest and have no stated maturity.

+ References

+ Details

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

- Definition

The aggregate amount of all domestic and foreign noninterest-bearing deposits liabilities held by the entity.

+ References

+ Details

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