XML 21 R57.htm IDEA: XBRL DOCUMENT v2.4.0.8

Fair Value Measurements - Quantitative Information about Level 3 Fair Value Measurements (Detail) (Fair Value, Measurements, Nonrecurring [Member], Significant Unobservable Inputs (Level 3) [Member], USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Weighted-Average discount for lack of marketability	5.00%
Impaired Loans Asset, Net [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value assets	$ 3,863
Fair Value Measurements, Valuation Techniques	Property appraisals
Selling cost	10.00%
Other Real Estate Owned, Net [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value assets	$ 2,221
Fair Value Measurements, Valuation Techniques	Property appraisals
Selling cost	7.00%
Minimum [Member] | Impaired Loans Assets, Net [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount for lack of marketability	0.00%
Maximum [Member] | Impaired Loans Assets, Net [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount for lack of marketability	19.00%

X

- Definition

Fair value unobservable inputs weighted average discount for lack of marketability.

+ References

No definition available.

+ Details

Name:	fxnc_FairValueUnobservableInputsWeightedAverageDiscountForLackOfMarketability
Namespace Prefix:	fxnc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=25499696&loc=d3e19207-110258

+ Details

Name:	us-gaap_AssetsFairValueDisclosure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Details

Name:	us-gaap_FairValueInputsAssetsQuantitativeInformationLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Adjustment to the discount rate used to measure fair value for lack of ability to convert business interests into cash quickly.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (bbb)

-URI http://asc.fasb.org/extlink&oid=25499696&loc=d3e19207-110258

+ Details

Name:	us-gaap_FairValueInputsDiscountForLackOfMarketability
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Interest rate used to find the present value of an amount to be paid or received in the future as an input to measure fair value. For example, but not limited to, weighted average cost of capital (WACC), cost of capital, cost of equity and cost of debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (bbb)

-URI http://asc.fasb.org/extlink&oid=25499696&loc=d3e19207-110258

+ Details

Name:	us-gaap_FairValueInputsDiscountRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Description of the inputs and valuation technique(s) used to measure fair value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (bbb)

-URI http://asc.fasb.org/extlink&oid=25499696&loc=d3e19207-110258

+ Details

Name:	us-gaap_FairValueMeasurementsValuationTechniques
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration