Note 8 - Fair Value Measurements (Detail) - Assets and Liabilities at Fair Value (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Available for Sale Securities	$ 451,129	$ 526,743
Municipal Bonds [Member] | Fair Value, Inputs, Level 2 [Member]
Available for Sale Securities	86,380	77,313
Municipal Bonds [Member]
Available for Sale Securities	86,380	77,313
US Government Agencies Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Available for Sale Securities	40,124	49,082
US Government Agencies Debt Securities [Member]
Available for Sale Securities	40,124	49,082
Residential Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Available for Sale Securities	191,578	173,083
Residential Mortgage Backed Securities [Member]
Available for Sale Securities	191,578	173,083
Equity Securities, Other [Member] | Fair Value, Inputs, Level 1 [Member]
Available for Sale Securities	120	112
Equity Securities, Other [Member] | Fair Value, Inputs, Level 3 [Member]
Available for Sale Securities	229	230
Equity Securities, Other [Member]
Available for Sale Securities	349	342
Residential Mortgage Loan Long-Term [Member] | Fair Value, Inputs, Level 2 [Member]
Available for Sale Securities	132,698	226,923
Residential Mortgage Loan Long-Term [Member]
Available for Sale Securities	132,698	226,923
Fair Value, Inputs, Level 1 [Member]
Available for Sale Securities	120	112
Fair Value, Inputs, Level 2 [Member]
Available for Sale Securities	450,780	526,401
Fair Value, Inputs, Level 3 [Member]
Available for Sale Securities	$ 229	$ 230