Note 8 - Loans and the Allowance for Loan Losses (Detail) - Composition of the Loan Portfolio (USD $)	Jun. 30, 2012	Dec. 31, 2011	Jun. 30, 2011
Financing Receivable	$ 520,649,000	$ 621,021,000
Commercial Loans [Member]
Financing Receivable	50,914,000	62,609,000	129,771,000
Agricultural [Member]
Financing Receivable	22,392,000	61,251,000	64,354,000
Agricultural Real Estate [Member]
Financing Receivable	53,328,000	60,523,000	49,391,000
Commercial Real Estate Loans [Member]
Financing Receivable	230,902,000	235,103,000	201,571,000
Commercial Real Estate Development [Member]
Financing Receivable	30,124,000	58,279,000	75,126,000
Residential Real Estate Loans [Member]
Financing Receivable	91,793,000	97,172,000
Real Estate Loans [Member]
Financing Receivable	406,147,000	451,077,000
Consumer Loans [Member]
Financing Receivable	$ 41,196,000	$ 46,084,000