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) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2017	Mar. 31, 2016
Trust Preferred Securities [Member]
Beginning balance		$ 7,361
Ending balance		7,394
Fair Value, Inputs, Level 3 [Member] | Trust Preferred Securities [Member]
Beginning balance		7,361	$ 7,212
Net gain from fair value adjustment of financial assets	[1]	32	(60)
Net loss from fair value adjustment of financial liabilities	[1]
Increase in accrued interest payable
Change in unrealized gains (losses) included in other comprehensive income		1	(2)
Ending balance		7,394	7,150
Changes in unrealized gain (loss) held at period end		1	(2)
Fair Value, Inputs, Level 3 [Member] | Junior Subordinated Debentures [Member]
Beginning balance		33,959	29,018
Net gain from fair value adjustment of financial assets	[1]
Net loss from fair value adjustment of financial liabilities	[1]	570	(1,054)
Increase in accrued interest payable		7	13
Change in unrealized gains (losses) included in other comprehensive income
Ending balance		34,536	27,977
Changes in unrealized gain (loss) held at period end

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