Note 11 - 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 ($)		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Trust Preferred Securities [Member]
Beginning balance		$ 1,289,000	$ 1,162,000	$ 1,256,000	$ 1,110,000
Net gain from fair value adjustment of financial assets	[1]	15,000	25,000	47,000	77,000
Net loss from fair value adjustment of financial liabilities	[1]	0	0	0	0
Increase (decrease) in accrued interest receivable		(1,000)	1,000	0	1,000
Increase (decrease) in accrued interest payable		0	0	0	0
Change in unrealized gains included in other comprehensive income		0	0	0	0
Ending balance		1,303,000	1,188,000	1,303,000	1,188,000
Changes in unrealized gains held at period end		0	0	0	0
Junior Subordinated Debentures [Member]
Beginning balance		42,941,000	38,692,000	41,849,000	36,986,000
Net gain from fair value adjustment of financial assets	[1]	0	0	0	0
Net loss from fair value adjustment of financial liabilities	[1]	543,000	867,000	1,753,000	2,548,000
Increase (decrease) in accrued interest receivable		0	0	0	0
Increase (decrease) in accrued interest payable		(21,000)	26,000	(11,000)	51,000
Change in unrealized gains included in other comprehensive income		(49,000)	(19,000)	(177,000)	(19,000)
Ending balance		43,414,000	39,566,000	43,414,000	39,566,000
Changes in unrealized gains held at period end		$ 1,425,000	$ 1,248,000	$ 1,425,000	$ 1,248,000

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