Note 9 - Fair Value Measurements and Disclosures (Details) - Financial Assets Measured at Fair Value on a Recurring and Nonrecurring Basis (USD $)	Jun. 30, 2014	Dec. 31, 2013
Trading Securities
State and municipal securities	$ 4,531,000	$ 0
Securities available-for-sale
Available for Sale Securities	344,277,000	388,670,000
Total Recurring Fair Value Measurements	348,808,000	388,670,000
Nonrecurring fair value measurements
Nonrecurring Fair Value Measurements	2,584,000	3,626,000
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Trading Securities
State and municipal securities	4,531,000
Securities available-for-sale
Available for Sale Securities	79,120,000	87,199,000
US States and Political Subdivisions Debt Securities [Member]
Trading Securities
State and municipal securities	4,531,000
Securities available-for-sale
Available for Sale Securities	79,120,000	87,199,000
US Government Agencies Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available-for-sale
Available for Sale Securities	52,056,000	71,639,000
US Government Agencies Debt Securities [Member]
Securities available-for-sale
Available for Sale Securities	52,056,000	71,639,000
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available-for-sale
Available for Sale Securities	127,338,000	139,723,000
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Securities available-for-sale
Available for Sale Securities	127,338,000	139,723,000
Collateralized Mortgage Obligations [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available-for-sale
Available for Sale Securities	70,656,000	75,394,000
Collateralized Mortgage Obligations [Member]
Securities available-for-sale
Available for Sale Securities	70,656,000	75,394,000
Pooled Trust Preferred Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Securities available-for-sale
Available for Sale Securities	2,393,000	2,069,000
Pooled Trust Preferred Securities [Member]
Securities available-for-sale
Available for Sale Securities	2,393,000	2,069,000
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available-for-sale
Available for Sale Securities	6,055,000	6,021,000
Corporate Debt Securities [Member]
Securities available-for-sale
Available for Sale Securities	6,055,000	6,021,000
Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Securities available-for-sale
Available for Sale Securities	6,659,000	6,625,000
Equity Securities [Member]
Securities available-for-sale
Available for Sale Securities	6,659,000	6,625,000
Fair Value, Inputs, Level 1 [Member]
Securities available-for-sale
Available for Sale Securities	6,659,000	6,625,000
Total Recurring Fair Value Measurements	6,659,000	6,625,000
Fair Value, Inputs, Level 2 [Member]
Trading Securities
State and municipal securities	4,531,000
Securities available-for-sale
Available for Sale Securities	335,225,000	379,976,000
Total Recurring Fair Value Measurements	339,756,000	379,976,000
Fair Value, Inputs, Level 3 [Member] | Impaired Loans [Member]
Nonrecurring fair value measurements
Nonrecurring Fair Value Measurements	2,084,000	3,107,000
Fair Value, Inputs, Level 3 [Member] | Mortgage Servicing Rights [Member]
Nonrecurring fair value measurements
Nonrecurring Fair Value Measurements	500,000	519,000
Fair Value, Inputs, Level 3 [Member]
Securities available-for-sale
Available for Sale Securities	2,393,000	2,069,000
Total Recurring Fair Value Measurements	2,393,000	2,069,000
Nonrecurring fair value measurements
Nonrecurring Fair Value Measurements	2,584,000	3,626,000
Impaired Loans [Member]
Nonrecurring fair value measurements
Nonrecurring Fair Value Measurements	2,084,000	3,107,000
Mortgage Servicing Rights [Member]
Nonrecurring fair value measurements
Nonrecurring Fair Value Measurements	$ 500,000	$ 519,000