Note 3 - Loans and Allowance for Loan Losses - Activity for Troubled Debt Restructurings (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Commercial and Industrial [Member]
Beginning Balance	$ 1,537,000	$ 1,946,000	$ 1,503,000	$ 2,028,000
Charge-Offs	0	0	0	0
Payments	(1,537,000)	0	(1,662,000)	(101,000)
Transfers to ORE	0	0	0	0
Net Additions/Deletions	2,775,000	157,000	2,934,000	176,000
Ending Balance	2,775,000	2,103,000	2,775,000	2,103,000
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Beginning Balance	959,000	2,062,000	1,488,000	2,086,000
Charge-Offs	0	0	0	0
Payments	(25,000)	(26,000)	(554,000)	(50,000)
Transfers to ORE	0	0	0	0
Net Additions/Deletions	0	0	0	0
Ending Balance	934,000	2,036,000	934,000	2,036,000
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Owner Occupied Loan [Member]
Beginning Balance	879,000	1,369,000	906,000	1,400,000
Charge-Offs	0	0	0	0
Payments	(25,000)	(35,000)	(52,000)	(66,000)
Transfers to ORE	0	0	0	0
Net Additions/Deletions	804,000	97,000	804,000	97,000
Ending Balance	1,658,000	1,431,000	1,658,000	1,431,000
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Non Owner Occupied Loan [Member]
Beginning Balance	4,551,000	10,529,000	5,110,000	10,657,000
Charge-Offs	0	0	0	0
Payments	(20,000)	(94,000)	(143,000)	(222,000)
Transfers to ORE	0	0	0	0
Net Additions/Deletions	(3,967,000)	0	(4,403,000)	0
Ending Balance	564,000	10,435,000	564,000	10,435,000
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Multi Family and Residential Rental Loan [Member]
Beginning Balance	291,000	469,000	716,000	476,000
Charge-Offs	0	0	0	0
Payments	(160,000)	(8,000)	(273,000)	(15,000)
Transfers to ORE	0	0	0	0
Net Additions/Deletions	0	0	(312,000)	0
Ending Balance	131,000	461,000	131,000	461,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Commercial and Industrial [Member]
Beginning Balance	922,000	1,687,000	1,125,000	1,686,000
Charge-Offs	0	0	0	(48,000)
Payments	(46,000)	(43,000)	(279,000)	(43,000)
Transfers to ORE	0	0	0	0
Net Additions/Deletions	116,000	0	146,000	49,000
Ending Balance	992,000	1,644,000	992,000	1,644,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Beginning Balance	0	0	0	0
Charge-Offs	0	0	0	0
Payments	0	0	0	0
Transfers to ORE	0	0	0	0
Net Additions/Deletions	33,000	0	33,000	0
Ending Balance	33,000	0	33,000	0
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Owner Occupied Loan [Member]
Beginning Balance	996,000	1,455,000	900,000	1,652,000
Charge-Offs	0	0	(12,000)	0
Payments	(16,000)	(172,000)	(16,000)	(369,000)
Transfers to ORE	0	0	0	0
Net Additions/Deletions	0	0	108,000	0
Ending Balance	980,000	1,283,000	980,000	1,283,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Non Owner Occupied Loan [Member]
Beginning Balance	583,000	637,000	728,000	647,000
Charge-Offs	0	0	0	0
Payments	(39,000)	(12,000)	(184,000)	(22,000)
Transfers to ORE	(291,000)	0	(291,000)	0
Net Additions/Deletions	661,000	56,000	661,000	56,000
Ending Balance	914,000	681,000	914,000	681,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Multi Family and Residential Rental Loan [Member]
Beginning Balance	68,000	278,000	60,000	331,000
Charge-Offs	0	0	0	0
Payments	(5,000)	(11,000)	(5,000)	(64,000)
Transfers to ORE	0	0	0	0
Net Additions/Deletions	0	7,000	8,000	7,000
Ending Balance	63,000	274,000	63,000	274,000
Retail Portfolio Segment [Member] | Originated Loan [Member] | Home Equity and Other [Member]
Beginning Balance	706,000	146,000	385,000	146,000
Charge-Offs	0	0	0	0
Payments	(55,000)	(1,000)	(55,000)	(1,000)
Transfers to ORE	0	0	0	0
Net Additions/Deletions	399,000	184,000	720,000	184,000
Ending Balance	1,050,000	329,000	1,050,000	329,000
Retail Portfolio Segment [Member] | Originated Loan [Member] | One to Four Family Mortgages [Member]
Beginning Balance	154,000	126,000	157,000	128,000
Charge-Offs	0	0	0	0
Payments	(3,000)	(3,000)	(6,000)	(5,000)
Transfers to ORE	0	0	0	0
Net Additions/Deletions	0	40,000	0	40,000
Ending Balance	151,000	163,000	151,000	163,000
Retail Portfolio Segment [Member] | Acquired Loan [Member] | Home Equity and Other [Member]
Beginning Balance	206,000	161,000	208,000	141,000
Charge-Offs	(25,000)	0	(25,000)	0
Payments	(32,000)	(7,000)	(41,000)	(14,000)
Transfers to ORE	0	0	0	0
Net Additions/Deletions	53,000	26,000	60,000	53,000
Ending Balance	202,000	180,000	202,000	180,000
Retail Portfolio Segment [Member] | Acquired Loan [Member] | One to Four Family Mortgages [Member]
Beginning Balance	376,000	335,000	326,000	316,000
Charge-Offs	0	0	0	0
Payments	(3,000)	(2,000)	(7,000)	(3,000)
Transfers to ORE	0	0	0	0
Net Additions/Deletions	137,000	0	191,000	20,000
Ending Balance	$ 510,000	$ 333,000	$ 510,000	$ 333,000