Note 11 - Fair Value Measurements (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Note 11 - Fair Value Measurements (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]
Securities available-for-sale	$ 1,203,682	$ 1,318,935
Assets	1,205,318	1,320,838
Liabilities
Liabilities	13,569	9,633
US Treasury Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Note 11 - Fair Value Measurements (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]
Securities available-for-sale	350,183	664,004
US Treasury Securities [Member]
Note 11 - Fair Value Measurements (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]
Securities available-for-sale	350,183	664,004
Mortgage-backed Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Note 11 - Fair Value Measurements (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]
Securities available-for-sale	760,329	544,303
Mortgage-backed Securities [Member]
Note 11 - Fair Value Measurements (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]
Securities available-for-sale	760,329	544,303
Collateralized Mortgage Obligations [Member] | Fair Value, Inputs, Level 2 [Member]
Note 11 - Fair Value Measurements (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]
Securities available-for-sale	42	45
Collateralized Mortgage Obligations [Member]
Note 11 - Fair Value Measurements (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]
Securities available-for-sale	42	45
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Note 11 - Fair Value Measurements (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]
Securities available-for-sale	74,511	94,472
Corporate Debt Securities [Member]
Note 11 - Fair Value Measurements (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]
Securities available-for-sale	74,511	94,472
Mutual Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Note 11 - Fair Value Measurements (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]
Securities available-for-sale	5,921	5,866
Mutual Funds [Member]
Note 11 - Fair Value Measurements (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]
Securities available-for-sale	5,921	5,866
Preferred Stock of Government Sponsored Entities [Member] | Fair Value, Inputs, Level 2 [Member]
Note 11 - Fair Value Measurements (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]
Securities available-for-sale	3,946	3,224
Preferred Stock of Government Sponsored Entities [Member]
Note 11 - Fair Value Measurements (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]
Securities available-for-sale	3,946	3,224
Other Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Note 11 - Fair Value Measurements (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]
Securities available-for-sale	8,750	7,021
Other Equity Securities [Member]
Note 11 - Fair Value Measurements (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]
Securities available-for-sale	8,750	7,021
Warrant [Member] | Fair Value, Inputs, Level 3 [Member]
Note 11 - Fair Value Measurements (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]
Assets	21	27
Warrant [Member]
Note 11 - Fair Value Measurements (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]
Assets	21	27
Foreign Exchange Contract [Member] | Fair Value, Inputs, Level 2 [Member]
Note 11 - Fair Value Measurements (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]
Assets	1,615	1,876
Liabilities
Liabilities	4,959	5,007
Foreign Exchange Contract [Member]
Note 11 - Fair Value Measurements (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]
Assets	1,615	1,876
Liabilities
Liabilities	4,959	5,007
Interest Rate Swap [Member] | Fair Value, Inputs, Level 2 [Member]
Liabilities
Liabilities	8,610	4,626
Interest Rate Swap [Member]
Liabilities
Liabilities	8,610	4,626
Fair Value, Inputs, Level 1 [Member]
Note 11 - Fair Value Measurements (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]
Securities available-for-sale	356,104	669,870
Assets	356,104	669,870
Fair Value, Inputs, Level 2 [Member]
Note 11 - Fair Value Measurements (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]
Securities available-for-sale	847,578	649,065
Assets	849,193	650,941
Liabilities
Liabilities	13,569	9,633
Fair Value, Inputs, Level 3 [Member]
Note 11 - Fair Value Measurements (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]
Assets	$ 21	$ 27