XML 87 R84.htm IDEA: XBRL DOCUMENT v2.4.0.8

Note 14 - Financial Instruments with Off-Balance Sheet Risk (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Note 14 - Financial Instruments with Off-Balance Sheet Risk (Details) [Line Items]
Consumer Mortgage Loans Held for Sale	$ 16,737	$ 22,747
Potential Default Period After Sale of Loans to Investor	12 months
Loans Held-for-sale, Mortgages	1,276	2,796
Cash, Uninsured Amount	0
Mortgage Loans Sold with Potential Recourse [Member]
Note 14 - Financial Instruments with Off-Balance Sheet Risk (Details) [Line Items]
Fair Value Disclosure, Off-balance Sheet Risks, Amount, Liability	18,257	22,574
Locked-Rate Commitments [Member]
Note 14 - Financial Instruments with Off-Balance Sheet Risk (Details) [Line Items]
Consumer Mortgage Loans Held for Sale	$ 493

X

- Definition

Represents the total dollar amount of consumer mortgage loans originated during the period and that were sold or that the Company intends to sell in the near future.

+ References

No definition available.

+ Details

Name:	nksh_ConsumerMortgageLoansHeldForSale
Namespace Prefix:	nksh_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Details

Name:	nksh_Note14FinancialInstrumentswithOffBalanceSheetRiskDetailsLineItems
Namespace Prefix:	nksh_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The period during which the mortgagor defaults after the sale of loans to the investor.

+ References

No definition available.

+ Details

Name:	nksh_PotentialDefaultPeriodAfterSaleOfLoansToInvestor
Namespace Prefix:	nksh_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The amount of cash as of the balance sheet date that is not insured by the Federal Deposit Insurance Corporation.

+ References

No definition available.

+ Details

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

X

- Definition

The fair value of financial liabilities, which are not recognized in the financial statements (off-balance sheet) because they fail to meet some other criterion for recognition.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 825

-SubTopic 10

-Section 50

-Paragraph 10

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=28364263&loc=d3e13433-108611

+ Details

Name:	us-gaap_FairValueDisclosureOffbalanceSheetRisksAmountLiability
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Amount of mortgage loans held for sale. Excludes loans and leases covered under loss sharing agreements and loans classified as debt securities.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=28367877&loc=d3e4428-111522



Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.7(a)(3))

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878



Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 948

-SubTopic 310

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6490309&loc=d3e48678-111004



Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Permanent Investor

-URI http://asc.fasb.org/extlink&oid=6520390

+ Details

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