Note 6 - Fair Value Measurements (Details) - Available For Sale Investment Securities Measured At Fair Value On A Recurring Basis (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Note 6 - Fair Value Measurements (Details) - Available For Sale Investment Securities Measured At Fair Value On A Recurring Basis [Line Items]
Available For Sale Investment Securities	$ 561,506	$ 573,108
US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Note 6 - Fair Value Measurements (Details) - Available For Sale Investment Securities Measured At Fair Value On A Recurring Basis [Line Items]
Available For Sale Investment Securities	0	0
US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Note 6 - Fair Value Measurements (Details) - Available For Sale Investment Securities Measured At Fair Value On A Recurring Basis [Line Items]
Available For Sale Investment Securities	77,925	76,095
US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Note 6 - Fair Value Measurements (Details) - Available For Sale Investment Securities Measured At Fair Value On A Recurring Basis [Line Items]
Available For Sale Investment Securities	0	0
US Government-sponsored Enterprises Debt Securities [Member]
Note 6 - Fair Value Measurements (Details) - Available For Sale Investment Securities Measured At Fair Value On A Recurring Basis [Line Items]
Available For Sale Investment Securities	77,925	76,095
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Note 6 - Fair Value Measurements (Details) - Available For Sale Investment Securities Measured At Fair Value On A Recurring Basis [Line Items]
Available For Sale Investment Securities	0	0
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Note 6 - Fair Value Measurements (Details) - Available For Sale Investment Securities Measured At Fair Value On A Recurring Basis [Line Items]
Available For Sale Investment Securities	129,701	118,755
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Note 6 - Fair Value Measurements (Details) - Available For Sale Investment Securities Measured At Fair Value On A Recurring Basis [Line Items]
Available For Sale Investment Securities	0	0
US States and Political Subdivisions Debt Securities [Member]
Note 6 - Fair Value Measurements (Details) - Available For Sale Investment Securities Measured At Fair Value On A Recurring Basis [Line Items]
Available For Sale Investment Securities	129,701	118,755
Residential Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Note 6 - Fair Value Measurements (Details) - Available For Sale Investment Securities Measured At Fair Value On A Recurring Basis [Line Items]
Available For Sale Investment Securities	0	0
Residential Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Note 6 - Fair Value Measurements (Details) - Available For Sale Investment Securities Measured At Fair Value On A Recurring Basis [Line Items]
Available For Sale Investment Securities	346,345	370,439
Residential Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Note 6 - Fair Value Measurements (Details) - Available For Sale Investment Securities Measured At Fair Value On A Recurring Basis [Line Items]
Available For Sale Investment Securities	0	0
Residential Mortgage Backed Securities [Member]
Note 6 - Fair Value Measurements (Details) - Available For Sale Investment Securities Measured At Fair Value On A Recurring Basis [Line Items]
Available For Sale Investment Securities	346,345	370,439
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Note 6 - Fair Value Measurements (Details) - Available For Sale Investment Securities Measured At Fair Value On A Recurring Basis [Line Items]
Available For Sale Investment Securities	0	0
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Note 6 - Fair Value Measurements (Details) - Available For Sale Investment Securities Measured At Fair Value On A Recurring Basis [Line Items]
Available For Sale Investment Securities	5,837	5,826
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Note 6 - Fair Value Measurements (Details) - Available For Sale Investment Securities Measured At Fair Value On A Recurring Basis [Line Items]
Available For Sale Investment Securities	0	0
Corporate Debt Securities [Member]
Note 6 - Fair Value Measurements (Details) - Available For Sale Investment Securities Measured At Fair Value On A Recurring Basis [Line Items]
Available For Sale Investment Securities	5,837	5,826
Mutual Funds And Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Note 6 - Fair Value Measurements (Details) - Available For Sale Investment Securities Measured At Fair Value On A Recurring Basis [Line Items]
Available For Sale Investment Securities	1,698	1,993
Mutual Funds And Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Note 6 - Fair Value Measurements (Details) - Available For Sale Investment Securities Measured At Fair Value On A Recurring Basis [Line Items]
Available For Sale Investment Securities		0
Mutual Funds And Equity Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Note 6 - Fair Value Measurements (Details) - Available For Sale Investment Securities Measured At Fair Value On A Recurring Basis [Line Items]
Available For Sale Investment Securities	0	0
Mutual Funds And Equity Securities [Member]
Note 6 - Fair Value Measurements (Details) - Available For Sale Investment Securities Measured At Fair Value On A Recurring Basis [Line Items]
Available For Sale Investment Securities	1,698	1,993
Fair Value, Inputs, Level 1 [Member]
Note 6 - Fair Value Measurements (Details) - Available For Sale Investment Securities Measured At Fair Value On A Recurring Basis [Line Items]
Available For Sale Investment Securities	1,698	1,993
Fair Value, Inputs, Level 2 [Member]
Note 6 - Fair Value Measurements (Details) - Available For Sale Investment Securities Measured At Fair Value On A Recurring Basis [Line Items]
Available For Sale Investment Securities	559,808	571,115
Fair Value, Inputs, Level 3 [Member]
Note 6 - Fair Value Measurements (Details) - Available For Sale Investment Securities Measured At Fair Value On A Recurring Basis [Line Items]
Available For Sale Investment Securities	$ 0	$ 0