XML 49 R38.htm IDEA: XBRL DOCUMENT
v3.21.2

Note 3 - Allowance for Loan Losses, Nonperforming Assets and Impaired Loans - Loans by Credit Quality Indicator (Details) - USD ($) $ in Thousands | Jun. 30, 2021 | Dec. 31, 2020
--- | --- | ---
Real Estate Construction Portfolio Segment[Member] |  |  |  |
Loans, Collectively evaluated for impairment |  | $ 48,569 | $ 42,266 |
Consumer Real Estate Portfolio Segment [Member] |  |  |  |
Loans, Collectively evaluated for impairment |  | 196,022 | 181,588 |
Commercial Real Estate Portfolio Segment [Member] |  |  |  |
Loans, Collectively evaluated for impairment |  | 398,371 | 389,259 |
Commercial Non Real Estate Segment [Member] |  |  |  |
Loans, Collectively evaluated for impairment |  | 73,206 | 77,920 |
Consumer Non Real Estate Portfolio Segment [Member] |  |  |  |
Loans, Collectively evaluated for impairment |  | 31,894 | 33,108 |
Pass [Member] |  |  |  |
Loans, Collectively evaluated for impairment | [1] | 794,538 | 756,616 |
Pass [Member] | States Political Subdivisions [Member] |  |  |  |
Loans, Collectively evaluated for impairment |  | 52,370 | 40,983 |
Special Mention [Member] |  |  |  |
Loans, Collectively evaluated for impairment | [1] | 5,276 | 8,035 |
Classified Excluding Impaired [Member] |  |  |  |
Loans, Collectively evaluated for impairment | [1] | 618 | 473 |
Construction, 1-4 Family Residential [Member] | Pass [Member] | Real Estate Construction Portfolio Segment[Member] |  |  |  |
Loans, Collectively evaluated for impairment | [1] | 10,213 | 8,195 |
Construction, Other [Member] | Pass [Member] | Real Estate Construction Portfolio Segment[Member] |  |  |  |
Loans, Collectively evaluated for impairment | [1] | 38,356 | 34,071 |
Equity Lines [Member] | Pass [Member] | Consumer Real Estate Portfolio Segment [Member] |  |  |  |
Loans, Collectively evaluated for impairment | [1] | 13,071 | 13,903 |
Closed End First Liens [Member] | Pass [Member] | Consumer Real Estate Portfolio Segment [Member] |  |  |  |
Loans, Collectively evaluated for impairment |  | 102,692 | 92,241 | [1]
Closed End First Liens [Member] | Special Mention [Member] | Consumer Real Estate Portfolio Segment [Member] |  |  |  |
Loans, Collectively evaluated for impairment |  | 64 | 66 | [1]
Closed End First Liens [Member] | Classified Excluding Impaired [Member] | Consumer Real Estate Portfolio Segment [Member] |  |  |  |
Loans, Collectively evaluated for impairment |  | 243 | 284 | [1]
Closed End Junior Liens [Member] | Pass [Member] | Consumer Real Estate Portfolio Segment [Member] |  |  |  |
Loans, Collectively evaluated for impairment |  | 2,985 | 3,003 | [1]
Closed End Junior Liens [Member] | Special Mention [Member] | Consumer Real Estate Portfolio Segment [Member] |  |  |  |
Loans, Collectively evaluated for impairment |  | 0 | 0 | [1]
Closed End Junior Liens [Member] | Classified Excluding Impaired [Member] | Consumer Real Estate Portfolio Segment [Member] |  |  |  |
Loans, Collectively evaluated for impairment |  | 0 | 0 | [1]
Investor Owned Residential Real Estate [Member] | Pass [Member] | Consumer Real Estate Portfolio Segment [Member] |  |  |  |
Loans, Collectively evaluated for impairment | [1] | 76,341 | 71,450 |
Investor Owned Residential Real Estate [Member] | Special Mention [Member] | Consumer Real Estate Portfolio Segment [Member] |  |  |  |
Loans, Collectively evaluated for impairment | [1] | 626 | 641 |
Investor Owned Residential Real Estate [Member] | Classified Excluding Impaired [Member] | Consumer Real Estate Portfolio Segment [Member] |  |  |  |
Loans, Collectively evaluated for impairment | [1] |  | 0 |
Multifamily Real Estate [Member] | Pass [Member] | Commercial Real Estate Portfolio Segment [Member] |  |  |  |
Loans, Collectively evaluated for impairment | [1] | 104,507 | 87,455 |
Multifamily Real Estate [Member] | Special Mention [Member] | Commercial Real Estate Portfolio Segment [Member] |  |  |  |
Loans, Collectively evaluated for impairment | [1] | 258 | 265 |
Multifamily Real Estate [Member] | Classified Excluding Impaired [Member] | Commercial Real Estate Portfolio Segment [Member] |  |  |  |
Loans, Collectively evaluated for impairment | [1] |  | 0 |
Commercial Real Estate, Owner Occupied [Member] | Pass [Member] | Commercial Real Estate Portfolio Segment [Member] |  |  |  |
Loans, Collectively evaluated for impairment | [1] | 139,144 | 146,900 |
Commercial Real Estate, Owner Occupied [Member] | Special Mention [Member] | Commercial Real Estate Portfolio Segment [Member] |  |  |  |
Loans, Collectively evaluated for impairment | [1] | 542 | 543 |
Commercial Real Estate, Owner Occupied [Member] | Classified Excluding Impaired [Member] | Commercial Real Estate Portfolio Segment [Member] |  |  |  |
Loans, Collectively evaluated for impairment | [1] | 176 | 140 |
Commercial Real Estate Other [Member] | Pass [Member] | Commercial Real Estate Portfolio Segment [Member] |  |  |  |
Loans, Collectively evaluated for impairment | [1] | 149,958 | 147,436 |
Commercial Real Estate Other [Member] | Special Mention [Member] | Commercial Real Estate Portfolio Segment [Member] |  |  |  |
Loans, Collectively evaluated for impairment | [1] | 3,786 | 6,520 |
Commercial Real Estate Other [Member] | Classified Excluding Impaired [Member] | Commercial Real Estate Portfolio Segment [Member] |  |  |  |
Loans, Collectively evaluated for impairment | [1] |  | 0 |
Commercial and Industrial [Member] | Pass [Member] | Commercial Non Real Estate Segment [Member] |  |  |  |
Loans, Collectively evaluated for impairment | [1] | 73,118 | 77,892 |
Commercial and Industrial [Member] | Special Mention [Member] | Commercial Non Real Estate Segment [Member] |  |  |  |
Loans, Collectively evaluated for impairment | [1] |  | 0 |
Commercial and Industrial [Member] | Classified Excluding Impaired [Member] | Commercial Non Real Estate Segment [Member] |  |  |  |
Loans, Collectively evaluated for impairment | [1] | 88 | 28 |
Credit Card Receivable [Member] | Pass [Member] | Consumer Non Real Estate Portfolio Segment [Member] |  |  |  |
Loans, Collectively evaluated for impairment | [1] | 4,359 | 4,665 |
Automobile Loan [Member] | Pass [Member] | Consumer Non Real Estate Portfolio Segment [Member] |  |  |  |
Loans, Collectively evaluated for impairment | [1] | 11,585 | 12,024 |
Automobile Loan [Member] | Classified Excluding Impaired [Member] | Consumer Non Real Estate Portfolio Segment [Member] |  |  |  |
Loans, Collectively evaluated for impairment | [1] | 0 | 6 |
Other Consumer Loans [Member] | Pass [Member] | Consumer Non Real Estate Portfolio Segment [Member] |  |  |  |
Loans, Collectively evaluated for impairment | [1] | 15,839 | 16,398 |
Other Consumer Loans [Member] | Classified Excluding Impaired [Member] | Consumer Non Real Estate Portfolio Segment [Member] |  |  |  |
Loans, Collectively evaluated for impairment | [1] | $ 111 | $ 15 |
[1] | Excludes impaired, if any.

X
- Definition The balance of financing receivables that were collectively evaluated for impairment. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (h) -URI http://asc.fasb.org/extlink&oid=123577603&loc=SL6953423-111524 + Details
Name: | us-gaap_FinancingReceivableCollectivelyEvaluatedForImpairment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=nksh_RealEstateConstructionPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=nksh_ConsumerRealEstatePortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialRealEstatePortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=nksh_CommercialNonRealEstateSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=nksh_ConsumerNonRealEstatePortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InternalCreditAssessmentAxis=us-gaap_PassMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=nksh_StatesPoliticalSubdivisionsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InternalCreditAssessmentAxis=us-gaap_SpecialMentionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InternalCreditAssessmentAxis=nksh_ClassifiedExcludingImpairedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=nksh_Construction14FamilyResidentialMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=nksh_ConstructionOtherMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=nksh_EquityLinesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=nksh_ClosedEndFirstLiensMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=nksh_ClosedEndJuniorLiensMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=nksh_InvestorOwnedResidentialRealEstateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=nksh_MultifamilyRealEstateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=nksh_CommercialRealEstateOwnerOccupiedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=nksh_CommercialRealEstateOtherMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=nksh_CommercialAndIndustrialMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_CreditCardReceivablesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_AutomobileLoanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=nksh_OtherConsumerLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |