XML 110 R63.htm IDEA: XBRL DOCUMENT
v2.4.0.6

Allowance for Loan Losses (Details Textual) (USD $) | 12 Months Ended
--- | ---
Dec. 31, 2012 | Dec. 31, 2011 | Dec. 31, 2010
Allowance for Loan Losses (Textual) [Abstract] |  |  |
Troubled debt restructurings (TDRs) | $ 6,300,000 | $ 11,400,000 |
TDRs performing under the restructured terms | 1,600,000 | 4,800,000 |
Troubled debt restructuring loan subsequent default | 0 |  |
Non-accrual loans excluded from impaired loan disclosure | 13,000 | 103,000 | 2,000
Interest accrued on loan | $ 1,000 | $ 4,000 | $ 0

X
- Details
Name: | fxnc_AllowanceForLoanLossesTextualAbstract
Namespace Prefix: | fxnc_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Financing receivable non-accrual loans excluded from impaired loan disclosure. + References No definition available. + Details
Name: | fxnc_FinancingReceivableNonAccrualLoansExcludedFromImpairedLoanDisclosure
Namespace Prefix: | fxnc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Financing receivable subsequent default recorded investment. + References No definition available. + Details
Name: | fxnc_FinancingReceivableSubsequentDefaultRecordedInvestment
Namespace Prefix: | fxnc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Performing troubled debt restructurings. + References No definition available. + Details
Name: | fxnc_PerformingTroubledDebtRestructurings
Namespace Prefix: | fxnc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of investment in financing receivables (before modification) modified by troubled debt restructurings. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 33 -URI http://asc.fasb.org/extlink&oid=7512638&loc=SL6953676-111524 + Details
Name: | us-gaap_FinancingReceivableModificationsPreModificationRecordedInvestment1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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=7512638&loc=d3e5212-111524 + Details
Name: | us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration