XML 51 R38.htm IDEA: XBRL DOCUMENT
v3.24.3

Note 2 - Securities - Credit Quality Indicators for Held to Maturity Securities (Details) - USD ($) $ in Thousands | Sep. 30, 2024 | Dec. 31, 2023
--- | --- | ---
Amortized cost, held to maturity securities |  | $ 121,529 | $ 148,351
Moody's, Aaa Rating [Member] |  |  |
Amortized cost, held to maturity securities |  | 45,140 | 64,828
Moody's, Aa1/Aa2/Aa3 Rating [Member] |  |  |
Amortized cost, held to maturity securities |  | 8,161 | 8,842
Moody's, Baa1/ Baa2/ Baa3 Rating [Member] |  |  |
Amortized cost, held to maturity securities |  | 3,000 | 3,000
Not Rated - Agency [Member] |  |  |
Amortized cost, held to maturity securities | [1] | 65,229 | 71,681
US Treasury Securities [Member] |  |  |
Amortized cost, held to maturity securities |  | 19,535 | 39,085
US Treasury Securities [Member] | Moody's, Aaa Rating [Member] |  |  |
Amortized cost, held to maturity securities |  | 19,535 | 39,085
US Treasury Securities [Member] | Moody's, Aa1/Aa2/Aa3 Rating [Member] |  |  |
Amortized cost, held to maturity securities |  | 0 | 0
US Treasury Securities [Member] | Moody's, Baa1/ Baa2/ Baa3 Rating [Member] |  |  |
Amortized cost, held to maturity securities |  | 0 | 0
US Treasury Securities [Member] | Not Rated - Agency [Member] |  |  |
Amortized cost, held to maturity securities | [1] | 0 | 0
US Agency and Mortgage-backed Securities [Member] |  |  |
Amortized cost, held to maturity securities |  | 88,342 | 94,617
US Agency and Mortgage-backed Securities [Member] | Moody's, Aaa Rating [Member] |  |  |
Amortized cost, held to maturity securities |  | 23,113 | 22,936
US Agency and Mortgage-backed Securities [Member] | Moody's, Aa1/Aa2/Aa3 Rating [Member] |  |  |
Amortized cost, held to maturity securities |  | 0 | 0
US Agency and Mortgage-backed Securities [Member] | Moody's, Baa1/ Baa2/ Baa3 Rating [Member] |  |  |
Amortized cost, held to maturity securities |  | 0 | 0
US Agency and Mortgage-backed Securities [Member] | Not Rated - Agency [Member] |  |  |
Amortized cost, held to maturity securities | [1] | 65,229 | 71,681
US States and Political Subdivisions Debt Securities [Member] |  |  |
Amortized cost, held to maturity securities |  | 10,653 | 11,649
US States and Political Subdivisions Debt Securities [Member] | Moody's, Aaa Rating [Member] |  |  |
Amortized cost, held to maturity securities |  | 2,492 | 2,807
US States and Political Subdivisions Debt Securities [Member] | Moody's, Aa1/Aa2/Aa3 Rating [Member] |  |  |
Amortized cost, held to maturity securities |  | 8,161 | 8,842
US States and Political Subdivisions Debt Securities [Member] | Moody's, Baa1/ Baa2/ Baa3 Rating [Member] |  |  |
Amortized cost, held to maturity securities |  | 0 | 0
US States and Political Subdivisions Debt Securities [Member] | Not Rated - Agency [Member] |  |  |
Amortized cost, held to maturity securities | [1] | 0 | 0
Corporate Debt Securities [Member] |  |  |
Amortized cost, held to maturity securities |  | 2,999 | 3,000
Corporate Debt Securities [Member] | Moody's, Aaa Rating [Member] |  |  |
Amortized cost, held to maturity securities |  | 0 | 0
Corporate Debt Securities [Member] | Moody's, Aa1/Aa2/Aa3 Rating [Member] |  |  |
Amortized cost, held to maturity securities |  | 0 | 0
Corporate Debt Securities [Member] | Moody's, Baa1/ Baa2/ Baa3 Rating [Member] |  |  |
Amortized cost, held to maturity securities |  | 3,000 | 3,000
Corporate Debt Securities [Member] | Not Rated - Agency [Member] |  |  |
Amortized cost, held to maturity securities | [1] | $ 0 | $ 0
[1] | Generally considered not to have credit risk given the implied governmental guarantees associated with these agencies.

X
- Definition Amount, before allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity). + References Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef -Topic 310 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 7A -Publisher FASB -URI https://asc.fasb.org/1943274/2147481962/310-10-50-7A Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479344/326-20-45-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-5 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 14 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-14 + Details
Name: | us-gaap_HeldToMaturitySecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | srt_CreditRatingMoodysAxis=srt_MoodysAaaRatingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CreditRatingMoodysAxis=fxnc_MoodysAa1aa2aa3RatingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CreditRatingMoodysAxis=fxnc_MoodysBaa1Baa2Baa3RatingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CreditRatingMoodysAxis=fxnc_NotRatedAgencyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_USTreasurySecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=fxnc_USAgencyAndMortgagebackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_USStatesAndPoliticalSubdivisionsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_CorporateDebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |