Amount of (credit) provision related to estimated loss from loan transactions.

No definition available.

Name:	cznc_CreditProvisionForLoanAndLeaseLosses
Namespace Prefix:	cznc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Threshold for determining if a financing receivable with an estimated loss of $100,000 or more, will be individually evaluated for impairment.

+ References

No definition available.

+ Details

Name:	cznc_FinancingReceivableIndividuallyEvaluatedForImpairmentThresholdWithEstimatedLoss
Namespace Prefix:	cznc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Deferred amounts of principal payments on loans receivable related to loan modification programs offered to financial institution customers affected by COVID-19.

+ References

No definition available.

+ Details

Name:	cznc_FinancingReceivablePrincipalDeferredPayments
Namespace Prefix:	cznc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

+ References

No definition available.

+ Details

Name:	cznc_ImpairedFinancingReceivableRecordedInvestment1
Namespace Prefix:	cznc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of allowance for credit losses related to recorded investment.

+ References

No definition available.

+ Details

Name:	cznc_ImpairedFinancingReceivableRelatedAllowance1
Namespace Prefix:	cznc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of investment in impaired financing receivables for which there is a related allowance for credit losses.

+ References

No definition available.

+ Details

Name:	cznc_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment1
Namespace Prefix:	cznc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The amount of increase (decrease) in provision for loan losses during the period.

+ References

No definition available.

+ Details

Name:	cznc_IncreaseDecreaseInProvisionForLoanLosses
Namespace Prefix:	cznc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The amount of increase (decrease) in the provision for loan losses from collectively determined portion of allowance.

+ References

No definition available.

+ Details

Name:	cznc_IncreaseDecreaseInProvisionForLoanLossesFromCollectivelyDeterminedPortionOfAllowance
Namespace Prefix:	cznc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The amount of increase (decrease) in the provision for loan losses from unallocated portion of allowance.

+ References

No definition available.

+ Details

Name:	cznc_IncreaseDecreaseInProvisionForLoanLossesFromUnallocatedPortionOfAllowance
Namespace Prefix:	cznc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The amount of net charge offs related to a specific loan included in the provision for loan losses.

+ References

No definition available.

+ Details

Name:	cznc_IncreaseDecreaseInProvisionForLoanLossesNetChargeOffs
Namespace Prefix:	cznc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The amount of net charge related to specific loans included in the provision for loan losses.

+ References

No definition available.

+ Details

Name:	cznc_IncreaseDecreaseInProvisionForLoanLossesNetChargeRelatedToSpecificLoans
Namespace Prefix:	cznc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Interest and fee income generated by commercial and consumer loans which is taxable.

+ References

No definition available.

+ Details

Name:	cznc_InterestAndFeeIncomeLoansTaxable
Namespace Prefix:	cznc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The number of loan charged off during the period.

+ References

No definition available.

+ Details

Name:	cznc_NumberOfLoanChargedOff
Namespace Prefix:	cznc_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of loans related to a specific loans included in the provision for loan losses.

+ References

No definition available.

+ Details

Name:	cznc_ProvisionForLoanLossesInSpecificAllowanceOnLoans
Namespace Prefix:	cznc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The amount of net increase (decrease) in specific allowances on loans included in the provision for loan losses.

+ References

No definition available.

+ Details

Name:	cznc_ProvisionForLoanLossesNetIncreaseDecreaseInSpecificAllowanceOnLoans
Namespace Prefix:	cznc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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

- Definition

Amount excluding accrued interest, of allowance for credit loss on financing receivable. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 45
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=124255206&loc=SL82895884-210446

+ Details

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

- Definition

Amount of writeoff of financing receivable, charged against allowance for credit loss.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 13
-Subparagraph (d)
-URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919249-210447

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)(3)
-URI https://asc.fasb.org/extlink&oid=123577603&loc=SL6953423-111524

Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 55
-Paragraph 79
-URI https://asc.fasb.org/extlink&oid=124267575&loc=SL82922352-210448

+ Details

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

- Definition

Amortized cost, before allowance for credit loss, fee, and loan in process, of financing receivable. Excludes financing receivable covered under loss sharing agreement and net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 5
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919230-210447

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI https://asc.fasb.org/extlink&oid=124259787&loc=d3e4428-111522

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(7))
-URI https://asc.fasb.org/extlink&oid=126897435&loc=d3e534808-122878

+ Details

Name:	us-gaap_FinancingReceivableBeforeAllowanceForCreditLossAndFee
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amortized cost excluding accrued interest, before allowance for credit loss, of financing receivable. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 5
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919230-210447

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 45
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=124255206&loc=SL82895884-210446

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 3B
-URI https://asc.fasb.org/extlink&oid=124255953&loc=SL120267963-210447

+ Details

Name:	us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of financing receivable modified as troubled debt restructuring within previous 12 months, with subsequent payment default.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 34
-Subparagraph (a)(2)
-URI https://asc.fasb.org/extlink&oid=123577603&loc=SL6953682-111524

+ Details

Name:	us-gaap_FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of unamortized loan commitment, origination, and other costs (fees) and purchase premium (discount) on financing receivable recognized as adjustment to yield. Excludes financing receivable covered under loss sharing agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 4
-URI https://asc.fasb.org/extlink&oid=123577603&loc=d3e5074-111524

Reference 2: http://www.xbrl.org/2003/role/recommendedDisclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 20
-Section 50
-Paragraph 3
-URI https://asc.fasb.org/extlink&oid=84159169&loc=d3e10152-111534

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 20
-Section 45
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=6378536&loc=d3e10092-111533

+ Details

Name:	us-gaap_FinancingReceivableUnamortizedLoanCommitmentOriginationFeeAndPremiumDiscount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of unfunded portion of contractual agreement to lend funds to borrower for financing receivable modified as troubled debt restructuring.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=121585226&loc=d3e18794-111554

+ Details

Name:	us-gaap_LoansAndLeasesReceivableImpairedCommitmentToLend
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Reflects the carrying amount of loans deemed to be questionable as to collection on which no interest is continuing to be recognized.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 7
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=123577603&loc=d3e5111-111524

+ Details

Name:	us-gaap_LoansAndLeasesReceivableImpairedNonperformingNonaccrualOfInterest
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	us-gaap_InternalCreditAssessmentAxis=us-gaap_SubstandardMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditLossStatusAxis=us-gaap_FinancialAssetAcquiredWithCreditDeteriorationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=cznc_SmallBusinessAdministrationPaycheckProtectionProgramLoansCaresActMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_RealEstateLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_MajorCustomersAxis=cznc_LoanCustomerMajorWriteOffMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_UnfundedLoanCommitmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=cznc_PaycheckProtectionProgramFirstDrawMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=cznc_PaycheckProtectionProgramSecondDrawMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=cznc_CommercialAndIndustrialMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ClassOfFinancingReceivableTypeOfBorrowerAxis=cznc_TroubledDebtRestructuredDefaultedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_UnallocatedFinancingReceivablesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ResidentialPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

LOANS - Additional information (Details)	12 Months Ended
LOANS - Additional information (Details)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($) loan	Dec. 31, 2019 USD ($)
LOANS
Unamortized Loan Commitment and Origination Fees and Unamortized Discounts or Premiums, Total	$ 4,725,000	$ 4,247,000
Impaired Financing Receivable, with Related Allowance, Recorded Investment1	3,460,000	6,540,000
Specific allowances	453,000	740,000
Loans receivable	1,740,040,000	1,564,849,000
Recorded Investment	0	3,405,000	$ 240,000
Allowance for Loan losses	16,615,000	13,537,000	11,385,000	$ 9,836,000
Interest and fees	78,599,000	74,549,000	67,384,000
Financing receivable charge-offs	4,245,000	1,575,000	2,465,000
Provision (credit) for loan losses	7,255,000	3,661,000	3,913,000
Increase (decrease) in provision for loan losses	3,594,000
Amount of net charge related to specific loans	3,890,000	1,324,000
Amount of net increase (decrease) in specific allowances on loans	287,000	185,000
Amount of net charge offs related to a specific loan	4,177,000	1,509,000
Amount of increase (decrease) in the provision for loan losses from collectively determined portion of allowance	3,036,000	2,251,000
Amount of increase (decrease) in the provision for loan losses from unallocated portion of allowance	329,000	86,000
Recorded Investment	19,358,000	15,734,000
Financing Receivable, Troubled Debt Restructuring, Commitment to Lend	0	0
Substandard
LOANS
Loans receivable	41,827,000	30,706,000
Purchased Credit Impaired
LOANS
Loans receivable	1,027,000	6,558,000
Loans Modified, Recorded Investment	1,027,000	6,558,000
Small Business Administration - Paycheck Protection Program
LOANS
Unamortized Loan Commitment and Origination Fees and Unamortized Discounts or Premiums, Total	27,000
Contractual principal balances	195,000
Interest and fees	958,000	6,530,000	2,924,000
Recorded Investment	168,000
Real estate loan \| Loan Customer Major Write Off [Member]
LOANS
Financing receivable charge-offs	3,942,000
Unfunded Loan Commitment
LOANS
Allowance for Loan losses	0	0
Commercial
LOANS
Loans receivable	1,111,498,000	978,371,000
Allowance for Loan losses	11,298,000	8,293,000	6,308,000	4,788,000
Financing receivable charge-offs	4,092,000	1,464,000	2,343,000
Provision (credit) for loan losses	7,097,000	3,427,000	3,847,000
Loans classified as impaired and nonaccrual	10,799,000
Commercial \| Substandard
LOANS
Loans receivable	34,500,000	23,308,000
Commercial \| Maximum
LOANS
Threshold amount of loan balance for evaluating individual impairment loss	200,000
Commercial \| Purchased Credit Impaired
LOANS
Loans receivable	1,027,000	6,485,000
Commercial \| Loan Customer Major Write Off [Member]
LOANS
Financing receivable charge-offs			$ 2,219,000
Number of loan charged off \| loan			1
Commercial \| Paycheck Protection Program - 1st Draw
LOANS
Loans receivable	5,000	1,356,000
Allowance for Loan losses	0	0
Commercial \| Paycheck Protection Program - 1st Draw \| Substandard
LOANS
Loans receivable	0	0
Commercial \| Paycheck Protection Program - 1st Draw \| Purchased Credit Impaired
LOANS
Loans receivable	0	0
Commercial \| Paycheck Protection Program - 2nd Draw
LOANS
Loans receivable	163,000	25,508,000
Allowance for Loan losses	0	0
Commercial \| Paycheck Protection Program - 2nd Draw \| Substandard
LOANS
Loans receivable	0	0
Commercial \| Paycheck Protection Program - 2nd Draw \| Purchased Credit Impaired
LOANS
Loans receivable	0	0
Commercial \| Commercial and industrial
LOANS
Impaired Financing Receivable, with Related Allowance, Recorded Investment1	60,000	72,000
Specific allowances	26,000	72,000
Loans receivable	178,271,000	159,073,000
Allowance for Loan losses	2,909,000	2,723,000	$ 2,245,000	1,391,000
Financing receivable charge-offs	150,000	1,464,000	2,236,000
Provision (credit) for loan losses	336,000	1,922,000	3,074,000
Commercial \| Commercial and industrial \| Substandard
LOANS
Loans receivable	21,279,000	4,694,000
Commercial \| Commercial and industrial \| Purchased Credit Impaired
LOANS
Loans receivable	40,000	763,000
Commercial \| Real estate loan
LOANS
Impaired Financing Receivable, with Related Allowance, Recorded Investment1	3,400,000	6,468,000
Specific allowances	427,000	668,000
Loans receivable	682,249,000	569,840,000
Allowance for Loan losses	7,074,000	4,405,000	3,051,000	1,921,000
Financing receivable charge-offs	3,942,000	0	0
Provision (credit) for loan losses	6,611,000	1,352,000	1,130,000
Recorded Investment	2,654,000
Commercial \| Real estate loan \| Substandard
LOANS
Loans receivable		16,220,000
Commercial \| Real estate loan \| TDRs for which payment defaults occurred
LOANS
Specific allowances	427,000	427,000	416,000
Recorded Investment	3,400,000	3,405,000
Specific loans allowance	427,000
Commercial \| Real estate loan \| Purchased Credit Impaired
LOANS
Loans receivable		4,144,000
Unallocated
LOANS
Allowance for Loan losses	1,000,000	671,000	585,000	585,000
Financing receivable charge-offs	0	0	0
Provision (credit) for loan losses	329,000	86,000	0
Residential mortgage
LOANS
Loans receivable	609,106,000	569,346,000
Allowance for Loan losses	4,073,000	4,338,000	4,253,000	$ 4,182,000
Financing receivable charge-offs	0	11,000	0
Provision (credit) for loan losses	(284,000)	90,000	$ 27,000
Residential mortgage \| Substandard
LOANS
Loans receivable	7,241,000	7,358,000
Residential mortgage \| Maximum
LOANS
Threshold amount of loan balance for evaluating individual impairment loss	400,000
Residential mortgage \| Purchased Credit Impaired
LOANS
Loans receivable	0	$ 73,000
Residential mortgage \| Real estate loan
LOANS
Loans receivable	682,249,000
Residential mortgage \| Real estate loan \| Substandard
LOANS
Loans receivable	10,231,000
Residential mortgage \| Real estate loan \| Purchased Credit Impaired
LOANS
Loans receivable	$ 987,000