Note 8 - Changes in Accumulated Other Comprehensive Income (Loss) By Component (1) - Accumulated Other Comprehensive Loss (Details) - USD ($)		3 Months Ended		6 Months Ended				12 Months Ended
		Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016		Jun. 30, 2015		Dec. 31, 2015
Accumulated Net Investment Gain (Loss) Attributable to Parent [Member]
Balance	[1]			$ (2,562,000)		$ 82,000		$ 82,000
Unrealized gain on securities	[1]			2,863,000		(774,000)		(2,577,000)
Amounts reclassified from accumulated other comprehensive income to net income (2)	[1],[2]			(416,000)		(4,000)		(67,000)
Net current-period other comprehensive income	[1]			2,447,000		(778,000)		(2,644,000)
Balance	[1]	$ (115,000)	$ (696,000)	(115,000)		(696,000)		(2,562,000)
Accumulated Net Investment Gain (Loss) on Securities Transferred from Available-for-Sale to Held-to-Maturity [Member]
Balance	[1]			(603,000)		(714,000)		(714,000)
Unrealized gain on securities	[1]
Amounts reclassified from accumulated other comprehensive income to net income (2)	[1],[2]			61,000		66,000		111,000
Net current-period other comprehensive income	[1]			61,000		66,000		111,000
Balance	[1]	(542,000)	(648,000)	(542,000)		(648,000)		(603,000)
Balance	[1]			(3,165,000)		(632,000)		(632,000)
Unrealized gain on securities	[1]			2,863,000		(774,000)		(2,577,000)
Amounts reclassified from accumulated other comprehensive income to net income (2)	[1],[2]			(355,000)		62,000		44,000
Net current-period other comprehensive income		538,000	(1,155,000)	2,508,000	[1]	(712,000)	[1]	(2,533,000)	[1]
Balance	[1]	$ (657,000)	$ (1,344,000)	$ (657,000)		$ (1,344,000)		$ (3,165,000)

[1] All amounts are net of tax. Amounts in parentheses indicate reductions to other comprehensive income.

[2] Reclassification amounts are reported as gains on sales of investment securities, impairment losses, and amortization of net unrealized losses on the Consolidated Statement of Operations.