Note 10 - Fair Value of Financial Instruments - Assets and Liabilities Carried at Fair Value on a Recurring Basis, Classified Within Level 3 of the Valuation Hierarchy (Details) - Fair Value, Inputs, Level 3 [Member] - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Trust Preferred Securities [Member]
Beginning balance		$ 1,162	$ 7,394	$ 1,110	$ 7,361
Net gain from fair value adjustment of financial assets	[1]	25	48	77	81
Net loss from fair value adjustment of financial liabilities	[1]
Increase in accrued interest receivable		1		1
Increase in accrued interest payable
Change in unrealized gains (losses) included in other comprehensive income			2		2
Ending balance		1,188	7,444	1,188	7,444
Changes in unrealized gains (losses) held at period end			2		2
Junior Subordinated Debentures [Member]
Beginning balance		38,692	34,536	36,986	33,959
Net gain from fair value adjustment of financial assets	[1]
Net loss from fair value adjustment of financial liabilities	[1]	867	594	2,548	1,165
Increase in accrued interest receivable
Increase in accrued interest payable		26	7	51	13
Change in unrealized gains (losses) included in other comprehensive income		(19)		(19)
Ending balance		39,566	35,137	39,566	35,137
Changes in unrealized gains (losses) held at period end		$ (19)		$ (19)

[1] Totals in the table above are presented in the Consolidated Statement of Income under net gains (losses) from fair value adjustments.