Note 4 - Loans and Allowance for Loan Losses (Details) - Concentrations Within the Loan Portfolio (USD $)
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Note 4 - Loans and Allowance for Loan Losses (Details) - Concentrations Within the Loan Portfolio [Line Items]      
Commercial real estate loans to lessors of non-residential buildings $ 2,089,277,000 $ 1,053,243,000 $ 1,041,189,000
Commercial Real Estate Loans to Lessors of Non-Residential Buildings [Member]      
Note 4 - Loans and Allowance for Loan Losses (Details) - Concentrations Within the Loan Portfolio [Line Items]      
Commercial real estate loans to lessors of non-residential buildings $ 480,170,000 $ 299,446,000  
Commercial real estate loans to lessors of non-residential buildings 23.00% 28.40%