Document and Entity Information	6 Months Ended
	Jun. 30, 2012	Aug. 14, 2012
Entity Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2012
Document Fiscal Year Focus	2012
Document Fiscal Period Focus	Q2
Trading Symbol	CDBK
Entity Registrant Name	Cardinal Bankshares Corporation
Entity Central Index Key	0001022759
Current Fiscal Year End Date	--12-31
Entity Filer Category	Smaller Reporting Company
Entity Common Stock, Shares Outstanding		1,535,733