Note 9 - Fair Value Measurements and Disclosures (Details) - Financial Assets Measured at Fair Value on a Recurring and Nonrecurring Basis (USD $)	Sep. 30, 2013	Dec. 31, 2012
Securities available-for-sale
Securities available-for-sale	$ 407,248,000	$ 401,502,000
Recurring fair value measurements	407,248,000	401,502,000
Nonrecurring fair value measurements
Nonrecurring fair value measurements	5,762,000	6,280,000
US Government Agencies Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available-for-sale
Securities available-for-sale	78,124,000	104,130,000
US Government Agencies Debt Securities [Member]
Securities available-for-sale
Securities available-for-sale	78,124,000	104,130,000
State and Municipal [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available-for-sale
Securities available-for-sale	88,873,000	86,789,000
State and Municipal [Member]
Securities available-for-sale
Securities available-for-sale	88,873,000	86,789,000
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available-for-sale
Securities available-for-sale	147,425,000	107,973,000
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Securities available-for-sale
Securities available-for-sale	147,425,000	107,973,000
Collateralized Mortgage Obligations [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available-for-sale
Securities available-for-sale	79,766,000	94,091,000
Collateralized Mortgage Obligations [Member]
Securities available-for-sale
Securities available-for-sale	79,766,000	94,091,000
Pooled Trust Preferred Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Securities available-for-sale
Securities available-for-sale	2,169,000	1,962,000
Pooled Trust Preferred Securities [Member]
Securities available-for-sale
Securities available-for-sale	2,169,000	1,962,000
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available-for-sale
Securities available-for-sale	6,007,000	2,502,000
Corporate Debt Securities [Member]
Securities available-for-sale
Securities available-for-sale	6,007,000	2,502,000
Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Securities available-for-sale
Securities available-for-sale	4,884,000	4,055,000
Equity Securities [Member]
Securities available-for-sale
Securities available-for-sale	4,884,000	4,055,000
Impaired Loans [Member] | Fair Value, Inputs, Level 3 [Member]
Nonrecurring fair value measurements
Nonrecurring fair value measurements	5,239,000	5,832,000
Impaired Loans [Member]
Nonrecurring fair value measurements
Nonrecurring fair value measurements	5,239,000	5,832,000
Mortgage Servicing Rights [Member] | Fair Value, Inputs, Level 3 [Member]
Nonrecurring fair value measurements
Nonrecurring fair value measurements	523,000	448,000
Mortgage Servicing Rights [Member]
Nonrecurring fair value measurements
Nonrecurring fair value measurements	523,000	448,000
Fair Value, Inputs, Level 1 [Member]
Securities available-for-sale
Securities available-for-sale	4,884,000	4,055,000
Recurring fair value measurements	4,884,000	4,055,000
Fair Value, Inputs, Level 2 [Member]
Securities available-for-sale
Securities available-for-sale	400,195,000	395,485,000
Recurring fair value measurements	400,195,000	395,485,000
Fair Value, Inputs, Level 3 [Member]
Securities available-for-sale
Securities available-for-sale	2,169,000	1,962,000
Recurring fair value measurements	2,169,000	1,962,000
Nonrecurring fair value measurements
Nonrecurring fair value measurements	$ 5,762,000	$ 6,280,000