XML 87 R74.htm IDEA: XBRL DOCUMENT
v3.22.0.1

Note 9 - Income Taxes - Components of Net Deferred Tax Assets (Details) - USD ($) $ in Thousands | Dec. 31, 2021 | Dec. 31, 2020
--- | --- | ---
Deferred tax assets: |  |
Allowance for loan losses and unearned fee income | $ 1,774 | $ 1,938
Valuation allowance on other real estate owned | 186 | 188
Defined benefit plan | 1,837 | 2,697
Deferred compensation and other liabilities | 899 | 866
Lease accounting | 327 | 423
SBA fees | 9 | 191
Total deferred tax assets | 5,032 | 6,303
Deferred tax liabilities: |  |
Fixed assets | (415) | (424)
Goodwill | (1,228) | (1,228)
Defined benefit plan, prepaid portion | (2,021) | (2,186)
Net unrealized gain on securities available for sale | (759) | (3,500)
Lease accounting | (321) | (419)
Discount accretion of securities | (27) | (15)
Total deferred tax liabilities | (4,771) | (7,772)
Net deferred tax assets | $ 261 |
Net deferred tax liabilities |  | $ (1,469)

X
- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from leases. + References No definition available. + Details
Name: | nksh_DeferredTaxAssetsLeases
Namespace Prefix: | nksh_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from SBA fees. + References No definition available. + Details
Name: | nksh_DeferredTaxAssetsSBAFees
Namespace Prefix: | nksh_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of deferred tax liability attributable to discount accretion of securities. + References No definition available. + Details
Name: | nksh_DeferredTaxLiabilitiesDiscountAccretionOfSecurities
Namespace Prefix: | nksh_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of deferred tax liability attributable to taxable temporary differences from unrealized gains on available for sale securities. + References No definition available. + Details
Name: | nksh_DeferredTaxLiabilitiesUnrealizedGainsOnAvailableForSaleSecurities
Namespace Prefix: | nksh_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of deferred tax liability attributable to taxable temporary differences. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(26)(b)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32537-109319 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(15)(b)(2)) -URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910 Reference 4: 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(15)(2)) -URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878 Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(26)(a)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_DeferredIncomeTaxLiabilities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32537-109319 + Details
Name: | us-gaap_DeferredTaxAssetsGross
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_DeferredTaxAssetsGrossAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount, after allocation of valuation allowances and deferred tax liability, of deferred tax asset attributable to deductible differences and carryforwards, without jurisdictional netting. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32537-109319 + Details
Name: | us-gaap_DeferredTaxAssetsLiabilitiesNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount, before allocation of valuation allowance, of deferred tax asset attributable to deductible temporary differences from compensation and benefits, classified as other. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32632-109319 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32621-109319 + Details
Name: | us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsOther
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from pension benefits. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32621-109319 + Details
Name: | us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsPensions
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from loss reserves other than estimated credit losses. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32632-109319 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32621-109319 + Details
Name: | us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsLossReserves
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount, before allocation of valuation allowance, of deferred tax asset attributable to deductible temporary difference from allowance for credit loss on financing receivable. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32632-109319 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32621-109319 + Details
Name: | us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsProvisionForLoanLosses
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount, after deferred tax asset, of deferred tax liability attributable to taxable differences without jurisdictional netting. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 45 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=123427490&loc=d3e31931-109318 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32537-109319 + Details
Name: | us-gaap_DeferredTaxLiabilities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_DeferredTaxLiabilitiesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of deferred tax liability attributable to taxable temporary differences from goodwill. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32632-109319 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32621-109319 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 740 -Section 25 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=123403335&loc=d3e9972-128506 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 740 -Section 25 -Paragraph 9 -URI http://asc.fasb.org/extlink&oid=123403335&loc=d3e9979-128506 + Details
Name: | us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsGoodwill
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of deferred tax liability attributable to taxable temporary differences from leasing arrangements. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32632-109319 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32621-109319 + Details
Name: | us-gaap_DeferredTaxLiabilitiesLeasingArrangements
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of deferred tax consequences attributable to taxable temporary differences derived from prepaid expenses. + References No definition available. + Details
Name: | us-gaap_DeferredTaxLiabilitiesPrepaidExpenses
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of deferred tax liability attributable to taxable temporary differences from property, plant, and equipment. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32621-109319 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32632-109319 + Details
Name: | us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant