Note 15 - Balance Sheet Offsetting (Details) - Financial Instruments that are Eligible for Offset in the Consolidated Balance Sheet (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Liabilities:
Gross amounts of recognized liabilities	$ 400,000	$ 450,000
Net amounts of liabilities presented in the statement of financial position	400,000	450,000
Collateral posted	(400,000)	(450,000)
Derivatives-Gross amounts of recognized liabilities	8,610	4,626
Derivatives-Net amounts of liabilities presented in the statement of financial position	8,610	4,626
Derivatives-Collateral posted	$ (8,610)	$ (4,626)