Note 5 - Major Classes of Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Accounts Notes And Loans Receivable [Line Items]
Loans and leases receivable	$ 927,147	$ 921,856
Net deferred (fees) costs	(677)	(1,814)
Loans receivable	926,470	920,042
Commercial Portfolio Segment [Member] \| Commercial and Industrial [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans and leases receivable	148,610	227,431
Commercial Portfolio Segment [Member] \| Construction Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans and leases receivable	55,855	57,594
Commercial Portfolio Segment [Member] \| Secured by Commercial Real Estate [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans and leases receivable	451,404	377,586
Commercial Portfolio Segment [Member] \| Secured by Residential Real Estate [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans and leases receivable	84,741	81,897
State and Political Subdivisions Portfolio Segment [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans and leases receivable	19,775	25,302
Retail Portfolio Segment [Member] \| Consumer Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans and leases receivable	4,699	5,364
Retail Portfolio Segment [Member] \| Family Residential Mortgages [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans and leases receivable	100,281	82,739
Retail Portfolio Segment [Member] \| Home Equity Loans and Lines [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans and leases receivable	$ 61,782	$ 63,943

Net unearned (fees) costs on loans and leases receivable.

No definition available.

Name:	qnbc_LoansAndLeasesReceivableNetUnearnedFeesCosts
Namespace Prefix:	qnbc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- 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 before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

+ References

+ Details

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

- Definition

Amount before allowance and after deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=124259787&loc=d3e4428-111522

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=123577603&loc=d3e5074-111524

+ Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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