XML 57 R45.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Allowance for Loan Losses - Impaired Loans and Related Allowance (Detail) - USD ($) $ in Thousands | 3 Months Ended | 12 Months Ended
--- | --- | ---
Mar. 31, 2018 | Mar. 31, 2017 | Dec. 31, 2017
Financing Receivable, Impaired [Line Items] |  |  |
Unpaid Principal Balance | $ 3,947 | $ 5,219 | $ 4,575
Recorded Investment with No Allowance | 3,530 | 4,428 | 3,811
Recorded Investment with Allowance | 0 | 85 | 0
Total Recorded Investment | 3,530 | 4,513 | 3,811
Related Allowance | 0 | 31 | 0
Average Recorded Investment | 3,894 | 4,756 | 4,656
Interest Income Recognized | 48 | 49 | 232
Real estate loans | Construction and Land Development |  |  |
Financing Receivable, Impaired [Line Items] |  |  |
Unpaid Principal Balance | 992 | 2,455 | 1,627
Recorded Investment with No Allowance | 874 | 2,022 | 1,150
Recorded Investment with Allowance | 0 | 0 | 0
Total Recorded Investment | 874 | 2,022 | 1,150
Related Allowance | 0 | 0 | 0
Average Recorded Investment | 1,257 | 1,922 | 1,814
Interest Income Recognized | 13 | 13 | 63
Real estate loans | Secured by 1-4 Family Residential |  |  |
Financing Receivable, Impaired [Line Items] |  |  |
Unpaid Principal Balance | 1,417 | 1,469 | 1,387
Recorded Investment with No Allowance | 1,332 | 1,358 | 1,307
Recorded Investment with Allowance | 0 | 85 | 0
Total Recorded Investment | 1,332 | 1,443 | 1,307
Related Allowance | 0 | 31 | 0
Average Recorded Investment | 1,299 | 1,781 | 1,637
Interest Income Recognized | 15 | 16 | 64
Real estate loans | Other real estate loans |  |  |
Financing Receivable, Impaired [Line Items] |  |  |
Unpaid Principal Balance | 1,464 | 1,206 | 1,483
Recorded Investment with No Allowance | 1,263 | 977 | 1,289
Recorded Investment with Allowance | 0 | 0 | 0
Total Recorded Investment | 1,263 | 977 | 1,289
Related Allowance | 0 | 0 | 0
Average Recorded Investment | 1,274 | 980 | 1,137
Interest Income Recognized | 19 | 19 | 95
Commercial and industrial loans |  |  |
Financing Receivable, Impaired [Line Items] |  |  |
Unpaid Principal Balance | 74 | 89 | 78
Recorded Investment with No Allowance | 61 | 71 | 65
Recorded Investment with Allowance | 0 | 0 | 0
Total Recorded Investment | 61 | 71 | 65
Related Allowance | 0 | 0 | 0
Average Recorded Investment | 64 | 73 | 68
Interest Income Recognized | $ 1 | $ 1 | $ 10

X
- Definition Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually 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 (g) -URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524 + Details
Name: | us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_FinancingReceivableImpairedLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The balance of financing receivables that were individually 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=84173941&loc=SL6953423-111524 + Details
Name: | us-gaap_FinancingReceivableIndividuallyEvaluatedForImpairment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5212-111524 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 17 -URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5258-111524 + Details
Name: | us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of interest income recognized that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5212-111524 + Details
Name: | us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of unpaid principal balance of impaired financing receivables with related allowance for credit losses and without related allowance for credit losses. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (a)(4) -URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5212-111524 + Details
Name: | us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of investment in impaired financing receivables for which there is no related allowance for credit losses. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 14A -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953550-111524 + Details
Name: | us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of investment in impaired financing receivables for which there is a related allowance for credit losses. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 14A -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953550-111524 + Details
Name: | us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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

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

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

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

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