Note 5 - Allowance for Loan Losses (Details) (USD $)	Jun. 30, 2014		Dec. 31, 2013
Note 5 - Allowance for Loan Losses (Details) [Line Items]
Financing Receivable, Net	$ 542,456,000	[1]	$ 542,660,000	[2]
Doubtful [Member]
Note 5 - Allowance for Loan Losses (Details) [Line Items]
Financing Receivable, Net	0		0
Unlikely to be Collected Financing Receivable [Member]
Note 5 - Allowance for Loan Losses (Details) [Line Items]
Financing Receivable, Net	0		0
Pass [Member] | CVBK [Member]
Note 5 - Allowance for Loan Losses (Details) [Line Items]
Financing Receivable, Net	102,440,000		115,270,000
Pass [Member]
Note 5 - Allowance for Loan Losses (Details) [Line Items]
Financing Receivable, Net	488,927,000		484,364,000
Special Mention [Member] | CVBK [Member]
Note 5 - Allowance for Loan Losses (Details) [Line Items]
Financing Receivable, Net	2,820,000		3,300,000
Special Mention [Member]
Note 5 - Allowance for Loan Losses (Details) [Line Items]
Financing Receivable, Net	10,988,000		11,901,000
Substandard [Member] | CVBK [Member]
Note 5 - Allowance for Loan Losses (Details) [Line Items]
Financing Receivable, Net	14,140,000		17,770,000
Substandard [Member]
Note 5 - Allowance for Loan Losses (Details) [Line Items]
Financing Receivable, Net	37,871,000		42,004,000
Substandard Nonaccural [Member] | CVBK [Member]
Note 5 - Allowance for Loan Losses (Details) [Line Items]
Financing Receivable, Net	641,000		652,000
Substandard Nonaccural [Member]
Note 5 - Allowance for Loan Losses (Details) [Line Items]
Financing Receivable, Net	$ 4,670,000		$ 4,391,000

[1] At June 30, 2014, the Corporation did not have any loans classified as Doubtful or Loss.

[2] At December 31, 2013, the Corporation did not have any loans classified as Doubtful or Loss.