Note 12 - Derivative Financial Instruments - Effect of Master Netting Arrangements on Derivative Assets and Liabilities in the Consolidated Statements of Condition (Details) - Interest Rate Swap [Member] - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Interest Rate Swaps, Gross Amount of Recognized Assets	$ 156	$ 15,961
Interest Rate Swaps, Gross Amount Offset in the Statement of Condition	0	0
Interest Rate Swaps, Net Amount of Assets Presented in the Statement of Condition	156	15,961
Interest Rate Swaps, Financial Instruments	0	0
Interest Rate Swaps, Cash Collateral Received	0	14,960
Interest Rate Swaps, Net Amount	156	1,001
Interest Rate Swaps, Gross Amount of Recognized Liabilities	30,988	2,239
Interest Rate Swaps, Gross Amount Offset in the Statement of Condition	0
Interest Rate Swaps, Net Amount of Liabilities Presented in the Statement of Condition	30,988	2,239
Interest Rate Swaps, Financial Instruments	31,070	0
Interest Rate Swaps, Cash Collateral Received	0	0
Interest Rate Swaps, Net Amount	$ (82)	2,239
Interest Rate Swaps, Gross Amount Offset in the Statement of Condition		$ 0