Note 18 - Fair Value of Financial Instruments - Fair Value Measured on a Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Assets	$ 867,731	$ 993,445
Liabilities	37,345	33,332
Fair Value, Inputs, Level 1 [Member]
Assets
Liabilities
Fair Value, Inputs, Level 2 [Member]
Assets	860,370	986,233
Liabilities	3,386	4,314
Fair Value, Inputs, Level 3 [Member]
Assets	7,361	7,212
Liabilities	33,959	29,018
Collateralized Mortgage Backed Securities [Member]
Assets	516,476	668,740
Collateralized Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Assets
Collateralized Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Assets	516,476	668,740
Collateralized Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Assets
Other Securities [Member]
Assets	344,905	324,657
Other Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Assets
Other Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Assets	337,544	317,445
Other Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Assets	7,361	7,212
Interest Rate Swap [Member]
Assets	6,350	48
Liabilities	3,386	4,314
Interest Rate Swap [Member] | Fair Value, Inputs, Level 1 [Member]
Assets
Liabilities
Interest Rate Swap [Member] | Fair Value, Inputs, Level 2 [Member]
Assets	6,350	48
Liabilities	3,386	4,314
Interest Rate Swap [Member] | Fair Value, Inputs, Level 3 [Member]
Assets
Liabilities
Borrowed Funds [Member]
Liabilities	33,959	29,018
Borrowed Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Liabilities
Borrowed Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Liabilities
Borrowed Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Liabilities	$ 33,959	$ 29,018