Note 2 - Investment Securities (Details) - Unrealized Loss Positions of Available-for-sale Securities - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Note 2 - Investment Securities (Details) - Unrealized Loss Positions of Available-for-sale Securities [Line Items]
Securities available-for-sale in a continuous unrealized loss position, less than 12 months, fair value	$ 8,752	$ 7,935
Securities available-for-sale in a continuous unrealized loss position, less than 12 months, unrealized loss	(81)	(74)
Securities available-for-sale in a continuous unrealized loss position, 12 months or more, fair value	7,836	13,322
Securities available-for-sale in a continuous unrealized loss position, 12 months or more, unrealized loss	(113)	(225)
Securities available-for-sale in a continuous unrealized loss position, fair value	16,588	21,257
Securities available-for-sale in a continuous unrealized loss position, unrealized loss	(194)	(299)
US Government Agencies Debt Securities [Member]
Note 2 - Investment Securities (Details) - Unrealized Loss Positions of Available-for-sale Securities [Line Items]
Securities available-for-sale in a continuous unrealized loss position, less than 12 months, fair value	2,844	5,568
Securities available-for-sale in a continuous unrealized loss position, less than 12 months, unrealized loss	(32)	(48)
Securities available-for-sale in a continuous unrealized loss position, 12 months or more, fair value	5,331	7,078
Securities available-for-sale in a continuous unrealized loss position, 12 months or more, unrealized loss	(71)	(132)
Securities available-for-sale in a continuous unrealized loss position, fair value	8,175	12,646
Securities available-for-sale in a continuous unrealized loss position, unrealized loss	(103)	(180)
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Note 2 - Investment Securities (Details) - Unrealized Loss Positions of Available-for-sale Securities [Line Items]
Securities available-for-sale in a continuous unrealized loss position, less than 12 months, fair value	2,842	742
Securities available-for-sale in a continuous unrealized loss position, less than 12 months, unrealized loss	(21)	(6)
Securities available-for-sale in a continuous unrealized loss position, 12 months or more, fair value	2,235	4,058
Securities available-for-sale in a continuous unrealized loss position, 12 months or more, unrealized loss	(36)	(58)
Securities available-for-sale in a continuous unrealized loss position, fair value	5,077	4,800
Securities available-for-sale in a continuous unrealized loss position, unrealized loss	(57)	(64)
US States and Political Subdivisions Debt Securities [Member]
Note 2 - Investment Securities (Details) - Unrealized Loss Positions of Available-for-sale Securities [Line Items]
Securities available-for-sale in a continuous unrealized loss position, less than 12 months, fair value	3,066	1,625
Securities available-for-sale in a continuous unrealized loss position, less than 12 months, unrealized loss	(28)	(20)
Securities available-for-sale in a continuous unrealized loss position, 12 months or more, fair value	270	2,186
Securities available-for-sale in a continuous unrealized loss position, 12 months or more, unrealized loss	(6)	(35)
Securities available-for-sale in a continuous unrealized loss position, fair value	3,336	3,811
Securities available-for-sale in a continuous unrealized loss position, unrealized loss	$ (34)	$ (55)