XML 90 R77.htm IDEA: XBRL DOCUMENT
v3.22.4

Note 11 - Minimum Regulatory Capital Requirement - Minimum Capital Requirements (Details) - National Bank of Blacksburg [Member] $ in Thousands | Dec. 31, 2022 USD ($) | Dec. 31, 2021 USD ($)
--- | --- | ---
Total capital (to risk weighted assets), actual, amount |  | $ 191,883 | $ 192,907
Total capital (to risk weighted assets), actual, ratio |  | 0.1757 | 0.1950
Total capital (to risk weighted assets), minimum capital requirement, amount | [1] | $ 114,671 | $ 103,898
Total capital (to risk weighted assets), minimum capital requirement, ratio | [1] | 0.1050 | 0.1050
Total capital (to risk weighted assets), minimum to be well capitalized, amount |  | $ 109,210 | $ 98,950
Total capital (to risk weighted assets), minimum to be well capitalized, ratio |  | 0.1000 | 0.1000
Tier 1 capital (to risk weighted assets), actual, amount |  | $ 183,623 | $ 185,187
Tier 1 capital (to risk weighted assets), actual, ratio |  | 0.1681 | 0.1872
Tier 1 capital (to risk weighted assets), minimum capital requirement, amount | [1] | $ 92,829 | $ 84,108
Tier 1 capital (to risk weighted assets), minimum capital requirement, ratio | [1] | 0.0850 | 0.0850
Tier 1 capital (to risk weighted assets), minimum to be well capitalized, amount |  | $ 87,368 | $ 79,160
Tier 1 capital (to risk weighted assets), minimum to be well capitalized, ratio |  | 0.0800 | 0.0800
Common equity tier 1 capital (to risk weighted assets), actual, amount |  | $ 183,623 | $ 185,187
Common equity tier 1 capital (to risk weighted assets), actual, ratio |  | 0.1681 | 0.1872
Common equity tier 1 capital (to risk weighted assets), minimum capital requirement, amount | [1] | $ 76,447 | $ 69,265
Common equity tier 1 capital (to risk weighted assets), minimum capital requirement, ratio | [1] | 7.00% | 7.00%
Common equity tier 1 capital (to risk weighted assets), minimum to be well capitalized, amount |  | $ 70,987 | $ 64,318
Common equity tier 1 capital (to risk weighted assets), minimum to be well capitalized, ratio |  | 6.50% | 6.50%
Tier 1 capital (to average assets), actual, amount |  | $ 183,623 | $ 185,187
Tier 1 capital (to average assets), actual, ratio |  | 0.1050 | 0.1116
Tier 1 capital (to average assets), minimum capital requirement, amount | [1] | $ 69,925 | $ 66,348
Tier 1 capital (to average assets), minimum capital requirement, ratio | [1] | 0.0400 | 0.0400
Tier 1 capital (to average assets), minimum to be well capitalized, amount |  | $ 87,406 | $ 82,935
Tier 1 capital (to average assets), minimum to be well capitalized, ratio |  | 0.0500 | 0.0500
[1] | Except with regard to NBB’s Tier 1 capital to average assets ratio, the minimum capital requirement includes the Basel III Capital Rules’ capital conservation buffer (2.50%) which is added to the minimum capital requirements for capital adequacy purposes. NBB’s capital conservation buffer consists of additional CET1 above regulatory minimum requirement. Failure to maintain the prescribed levels would result in limitations on capital distributions and discretionary bonuses to executives.

X
- Definition Amount of minimum Tier 1 risk-based capital required for capital requirement as defined by regulatory framework. + References No definition available. + Details
Name: | nksh_BankingRegulationTierOneRiskbasedCapitalCapitalRequirementMinimum
Namespace Prefix: | nksh_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Ratio of minimum Tier 1 risk-based capital to risk-weighted assets required for capital requirement as defined by regulatory framework. + References No definition available. + Details
Name: | nksh_BankingRegulationTierOneRiskbasedCapitalRatioMinimumCapitalRequirement
Namespace Prefix: | nksh_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | instant

X
- Definition The minimum amount of common equity tier 1 capital required for capital adequacy purposes under the regulatory framework for prompt corrective action. + References No definition available. + Details
Name: | nksh_CommonEquityTier1CapitalRequiredForCapitalAdequacyToRiskWeightedAssets
Namespace Prefix: | nksh_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition The common equity tier 1 risk based capital ratio (common equity tier 1 capital divided by risk weighted assets) required to be categorized as "well capitalized", in the regulatory framework for prompt corrective action. + References No definition available. + Details
Name: | nksh_CommonEquityTier1CapitalRequiredToBeWellCapitalizedToRiskWeightedAssets
Namespace Prefix: | nksh_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of total capital as defined by regulatory framework. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1 -Subparagraph (c)(1) -URI https://asc.fasb.org/extlink&oid=117337116&loc=SL5958568-112826 + Details
Name: | us-gaap_Capital
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of minimum total risk-based capital required for capital adequacy as defined by regulatory framework. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1 -Subparagraph (c)(1) -URI https://asc.fasb.org/extlink&oid=117337116&loc=SL5958568-112826 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1B -URI https://asc.fasb.org/extlink&oid=117337116&loc=SL5958570-112826 + Details
Name: | us-gaap_CapitalRequiredForCapitalAdequacy
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Ratio of minimum total risk-based capital to risk-weighted assets required for capital adequacy as defined by regulatory framework. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1B -URI https://asc.fasb.org/extlink&oid=117337116&loc=SL5958570-112826 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1 -Subparagraph (c)(1) -URI https://asc.fasb.org/extlink&oid=117337116&loc=SL5958568-112826 + Details
Name: | us-gaap_CapitalRequiredForCapitalAdequacyToRiskWeightedAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of minimum total risk-based capital categorized as well capitalized as defined by regulatory framework for prompt corrective action. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1 -Subparagraph (c)(1) -URI https://asc.fasb.org/extlink&oid=117337116&loc=SL5958568-112826 + Details
Name: | us-gaap_CapitalRequiredToBeWellCapitalized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Ratio of minimum total risk-based capital to risk-weighted assets categorized as well capitalized as defined by regulatory framework for prompt corrective action. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1 -Subparagraph (c)(1) -URI https://asc.fasb.org/extlink&oid=117337116&loc=SL5958568-112826 + Details
Name: | us-gaap_CapitalRequiredToBeWellCapitalizedToRiskWeightedAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | instant

X
- Definition Ratio of total risk-based capital to risk-weighted assets as defined by regulatory framework. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1 -Subparagraph (c)(1) -URI https://asc.fasb.org/extlink&oid=117337116&loc=SL5958568-112826 + Details
Name: | us-gaap_CapitalToRiskWeightedAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of Common Equity Tier 1 risk-based capital as defined by regulatory framework. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1 -Subparagraph (c)(1) -URI https://asc.fasb.org/extlink&oid=117337116&loc=SL5958568-112826 + Details
Name: | us-gaap_CommonEquityTierOneCapital
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Ratio of Common Equity Tier 1 risk-based capital to risk-weighted assets as defined by regulatory framework. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1 -Subparagraph (c)(1) -URI https://asc.fasb.org/extlink&oid=117337116&loc=SL5958568-112826 + Details
Name: | us-gaap_CommonEquityTierOneCapitalRatio
Namespace Prefix: | us-gaap_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of minimum Common Equity Tier 1 risk-based capital required for capital adequacy as defined by regulatory framework. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1 -Subparagraph (c)(1) -URI https://asc.fasb.org/extlink&oid=117337116&loc=SL5958568-112826 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1B -URI https://asc.fasb.org/extlink&oid=117337116&loc=SL5958570-112826 + Details
Name: | us-gaap_CommonEquityTierOneCapitalRequiredForCapitalAdequacy
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of minimum Common Equity Tier 1 risk-based capital categorized as well capitalized as defined by regulatory framework for prompt corrective action. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1 -Subparagraph (c)(1) -URI https://asc.fasb.org/extlink&oid=117337116&loc=SL5958568-112826 + Details
Name: | us-gaap_CommonEquityTierOneCapitalRequiredToBeWellCapitalized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of Tier 1 leverage capital as defined by regulatory framework. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1 -Subparagraph (c)(1) -URI https://asc.fasb.org/extlink&oid=117337116&loc=SL5958568-112826 + Details
Name: | us-gaap_TierOneLeverageCapital
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of minimum Tier 1 leverage capital required for capital adequacy as defined by regulatory framework. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1B -URI https://asc.fasb.org/extlink&oid=117337116&loc=SL5958570-112826 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1 -Subparagraph (c)(1) -URI https://asc.fasb.org/extlink&oid=117337116&loc=SL5958568-112826 + Details
Name: | us-gaap_TierOneLeverageCapitalRequiredForCapitalAdequacy
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Ratio of minimum Tier 1 leverage capital to average assets required for capital adequacy as defined by regulatory framework. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1B -URI https://asc.fasb.org/extlink&oid=117337116&loc=SL5958570-112826 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1 -Subparagraph (c)(1) -URI https://asc.fasb.org/extlink&oid=117337116&loc=SL5958568-112826 + Details
Name: | us-gaap_TierOneLeverageCapitalRequiredForCapitalAdequacyToAverageAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of minimum Tier 1 leverage capital categorized as well capitalized as defined by regulatory framework for prompt corrective action. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1 -Subparagraph (c)(1) -URI https://asc.fasb.org/extlink&oid=117337116&loc=SL5958568-112826 + Details
Name: | us-gaap_TierOneLeverageCapitalRequiredToBeWellCapitalized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Ratio of minimum Tier 1 leverage capital to average assets categorized as well capitalized as defined by regulatory framework for prompt corrective action. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1 -Subparagraph (c)(1) -URI https://asc.fasb.org/extlink&oid=117337116&loc=SL5958568-112826 + Details
Name: | us-gaap_TierOneLeverageCapitalRequiredToBeWellCapitalizedToAverageAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | instant

X
- Definition Ratio of Tier 1 capital to average assets as defined by regulatory framework. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1 -Subparagraph (c)(1) -URI https://asc.fasb.org/extlink&oid=117337116&loc=SL5958568-112826 + Details
Name: | us-gaap_TierOneLeverageCapitalToAverageAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of Tier 1 risk-based capital as defined by regulatory framework. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1 -Subparagraph (c)(1) -URI https://asc.fasb.org/extlink&oid=117337116&loc=SL5958568-112826 + Details
Name: | us-gaap_TierOneRiskBasedCapital
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of minimum Tier 1 risk-based capital categorized as well capitalized as defined by regulatory framework for prompt corrective action. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1 -Subparagraph (c)(1) -URI https://asc.fasb.org/extlink&oid=117337116&loc=SL5958568-112826 + Details
Name: | us-gaap_TierOneRiskBasedCapitalRequiredToBeWellCapitalized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Ratio of minimum Tier 1 risk-based capital to risk-weighted assets categorized as well capitalized as defined by regulatory framework for prompt corrective action. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1 -Subparagraph (c)(1) -URI https://asc.fasb.org/extlink&oid=117337116&loc=SL5958568-112826 + Details
Name: | us-gaap_TierOneRiskBasedCapitalRequiredToBeWellCapitalizedToRiskWeightedAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | instant

X
- Definition Ratio of Tier 1 risk-based capital to risk-weighted assets as defined by regulatory framework. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1 -Subparagraph (c)(1) -URI https://asc.fasb.org/extlink&oid=117337116&loc=SL5958568-112826 + Details
Name: | us-gaap_TierOneRiskBasedCapitalToRiskWeightedAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | dei_LegalEntityAxis=nksh_NationalBankOfBlacksburgMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |