XML 49 R38.htm IDEA: XBRL DOCUMENT
v3.5.0.2

Note 4 - Allowance for Loan Losses, Nonperforming Assets and Impaired Loans - Loans by Credit Quality Indicator (Details) - USD ($) | Sep. 30, 2016 | Dec. 31, 2015
--- | --- | ---
Construction, 1-4 Family Residential [Member] | Pass [Member] | Real Estate Construction Portfolio Segment[Member] |  |
Non-impaired gross loans | $ 14,169,000 | $ 10,626,000
Construction, 1-4 Family Residential [Member] | Special Mention [Member] | Real Estate Construction Portfolio Segment[Member] |  |
Non-impaired gross loans | 3,580,000 | 3,694,000
Construction, 1-4 Family Residential [Member] | Classified Excluding Impaired [Member] | Real Estate Construction Portfolio Segment[Member] |  |
Non-impaired gross loans | 0 | 0
Construction Other [Member] | Pass [Member] | Real Estate Construction Portfolio Segment[Member] |  |
Non-impaired gross loans | 22,168,000 | 33,213,000
Construction Other [Member] | Special Mention [Member] | Real Estate Construction Portfolio Segment[Member] |  |
Non-impaired gross loans | 0 | 0
Construction Other [Member] | Classified Excluding Impaired [Member] | Real Estate Construction Portfolio Segment[Member] |  |
Non-impaired gross loans | 0 | 0
Equity Lines [Member] | Pass [Member] | Consumer Real Estate Portfolio Segment [Member] |  |
Non-impaired gross loans | 16,631,000 | 16,236,000
Equity Lines [Member] | Special Mention [Member] | Consumer Real Estate Portfolio Segment [Member] |  |
Non-impaired gross loans | 39,000 | 15,000
Equity Lines [Member] | Classified Excluding Impaired [Member] | Consumer Real Estate Portfolio Segment [Member] |  |
Non-impaired gross loans | 13,000 | 87,000
Closed End First Liens [Member] | Pass [Member] | Consumer Real Estate Portfolio Segment [Member] |  |
Non-impaired gross loans | 82,284,000 | 78,614,000
Closed End First Liens [Member] | Special Mention [Member] | Consumer Real Estate Portfolio Segment [Member] |  |
Non-impaired gross loans | 1,061,000 | 708,000
Closed End First Liens [Member] | Classified Excluding Impaired [Member] | Consumer Real Estate Portfolio Segment [Member] |  |
Non-impaired gross loans | 1,114,000 | 1,370,000
Closed End Junior Liens [Member] | Pass [Member] | Consumer Real Estate Portfolio Segment [Member] |  |
Non-impaired gross loans | 5,006,000 | 4,983,000
Closed End Junior Liens [Member] | Special Mention [Member] | Consumer Real Estate Portfolio Segment [Member] |  |
Non-impaired gross loans | 16,000 | 55,000
Closed End Junior Liens [Member] | Classified Excluding Impaired [Member] | Consumer Real Estate Portfolio Segment [Member] |  |
Non-impaired gross loans | 56,000 | 61,000
Investor Owned Residential Real Estate [Member] | Pass [Member] | Consumer Real Estate Portfolio Segment [Member] |  |
Non-impaired gross loans | 43,271,000 | 39,616,000
Investor Owned Residential Real Estate [Member] | Special Mention [Member] | Consumer Real Estate Portfolio Segment [Member] |  |
Non-impaired gross loans | 29,000 | 31,000
Investor Owned Residential Real Estate [Member] | Classified Excluding Impaired [Member] | Consumer Real Estate Portfolio Segment [Member] |  |
Non-impaired gross loans | 743,000 | 766,000
Multifamily Real Estate [Member] | Pass [Member] | Commercial Real Estate Portfolio Segment [Member] |  |
Non-impaired gross loans | 98,654,000 | 77,060,000
Multifamily Real Estate [Member] | Special Mention [Member] | Commercial Real Estate Portfolio Segment [Member] |  |
Non-impaired gross loans | 458,000 | 0
Multifamily Real Estate [Member] | Classified Excluding Impaired [Member] | Commercial Real Estate Portfolio Segment [Member] |  |
Non-impaired gross loans | 1,287,000 | 1,804,000
Commercial Real Estate, Owner Occupied [Member] | Pass [Member] | Commercial Real Estate Portfolio Segment [Member] |  |
Non-impaired gross loans | 115,544,000 | 121,741,000
Commercial Real Estate, Owner Occupied [Member] | Special Mention [Member] | Commercial Real Estate Portfolio Segment [Member] |  |
Non-impaired gross loans | 1,230,000 | 1,165,000
Commercial Real Estate, Owner Occupied [Member] | Classified Excluding Impaired [Member] | Commercial Real Estate Portfolio Segment [Member] |  |
Non-impaired gross loans | 384,000 | 1,274,000
Commercial Real Estate Other [Member] | Pass [Member] | Commercial Real Estate Portfolio Segment [Member] |  |
Non-impaired gross loans | 99,028,000 | 93,701,000
Commercial Real Estate Other [Member] | Special Mention [Member] | Commercial Real Estate Portfolio Segment [Member] |  |
Non-impaired gross loans | 56,000 | 58,000
Commercial Real Estate Other [Member] | Classified Excluding Impaired [Member] | Commercial Real Estate Portfolio Segment [Member] |  |
Non-impaired gross loans | 0 | 0
Commercial and Industrial [Member] | Pass [Member] | Commercial Non Real Estate Segment [Member] |  |
Non-impaired gross loans | 39,177,000 | 35,652,000
Commercial and Industrial [Member] | Special Mention [Member] | Commercial Non Real Estate Segment [Member] |  |
Non-impaired gross loans | 1,550,000 | 285,000
Commercial and Industrial [Member] | Classified Excluding Impaired [Member] | Commercial Non Real Estate Segment [Member] |  |
Non-impaired gross loans | 546,000 | 543,000
Credit Card Receivable [Member] | Pass [Member] | Consumer Non Real Estate Portfolio Segment [Member] |  |
Non-impaired gross loans | 5,835,000 | 5,773,000
Credit Card Receivable [Member] | Special Mention [Member] | Consumer Non Real Estate Portfolio Segment [Member] |  |
Non-impaired gross loans | 0 | 0
Credit Card Receivable [Member] | Classified Excluding Impaired [Member] | Consumer Non Real Estate Portfolio Segment [Member] |  |
Non-impaired gross loans | 0 | 0
Automobile Loan [Member] | Pass [Member] | Consumer Non Real Estate Portfolio Segment [Member] |  |
Non-impaired gross loans | 14,251,000 | 12,414,000
Automobile Loan [Member] | Special Mention [Member] | Consumer Non Real Estate Portfolio Segment [Member] |  |
Non-impaired gross loans | 104,000 | 102,000
Automobile Loan [Member] | Classified Excluding Impaired [Member] | Consumer Non Real Estate Portfolio Segment [Member] |  |
Non-impaired gross loans | 168,000 | 138,000
Other Consumer Loans [Member] | Pass [Member] | Consumer Non Real Estate Portfolio Segment [Member] |  |
Non-impaired gross loans | 12,641,000 | 11,359,000
Other Consumer Loans [Member] | Special Mention [Member] | Consumer Non Real Estate Portfolio Segment [Member] |  |
Non-impaired gross loans | 58,000 | 31,000
Other Consumer Loans [Member] | Classified Excluding Impaired [Member] | Consumer Non Real Estate Portfolio Segment [Member] |  |
Non-impaired gross loans | 19,000 | 28,000
Pass [Member] | States Political Subdivisions [Member] |  |
Non-impaired gross loans | 45,957,000 | 51,335,000
Pass [Member] |  |
Non-impaired gross loans | 614,616,000 | 592,323,000
Special Mention [Member] | States Political Subdivisions [Member] |  |
Non-impaired gross loans | 0 | 0
Special Mention [Member] |  |
Non-impaired gross loans | 8,181,000 | 6,144,000
Classified Excluding Impaired [Member] | States Political Subdivisions [Member] |  |
Non-impaired gross loans | 0 | 0
Classified Excluding Impaired [Member] |  |
Non-impaired gross loans | 4,330,000 | 6,071,000
Real Estate Construction Portfolio Segment[Member] |  |
Non-impaired gross loans | 39,917,000 | 47,533,000
Consumer Real Estate Portfolio Segment [Member] |  |
Non-impaired gross loans | 150,263,000 | 142,542,000
Commercial Real Estate Portfolio Segment [Member] |  |
Non-impaired gross loans | 316,641,000 | 296,803,000
Commercial Non Real Estate Segment [Member] |  |
Non-impaired gross loans | 41,273,000 | 36,480,000
Consumer Non Real Estate Portfolio Segment [Member] |  |
Non-impaired gross loans | 33,076,000 | 29,845,000
Non-impaired gross loans | $ 627,127,000 | $ 604,538,000

X
- Definition The balance of financing receivables that were collectively evaluated for impairment. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (h) -URI http://asc.fasb.org/extlink&oid=66008989&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_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=nksh_Construction14FamilyResidentialMember
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_RealEstateConstructionPortfolioSegmentMember
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_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_FinancingReceivablePortfolioSegmentAxis=nksh_ConsumerRealEstatePortfolioSegmentMember
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_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialRealEstatePortfolioSegmentMember
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_FinancingReceivablePortfolioSegmentAxis=nksh_CommercialNonRealEstateSegmentMember
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_FinancingReceivablePortfolioSegmentAxis=nksh_ConsumerNonRealEstatePortfolioSegmentMember
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: |

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