Note 4 - Allowance for Loan Losses, Nonperforming Assets and Impaired Loans - Loans and Allowance for Loan Losses by Evaluation Method (Details) - USD ($)	Jun. 30, 2016	Dec. 31, 2015	Jun. 30, 2015	Dec. 31, 2014
Real Estate Construction Portfolio Segment[Member]
Individually evaluated for impairment	$ 0	$ 0
Collectively evaluated for impairment	515,000	576,000
Total	515,000	576,000	$ 476,000	$ 612,000
Individually evaluated for impairment	678,000	718,000
Collectively evaluated for impairment	41,656,000	47,533,000
Total	42,334,000	48,251,000
Consumer Real Estate Portfolio Segment [Member]
Individually evaluated for impairment	20,000	22,000
Collectively evaluated for impairment	1,756,000	1,844,000
Total	1,776,000	1,866,000	1,837,000	1,662,000
Individually evaluated for impairment	934,000	962,000
Collectively evaluated for impairment	146,654,000	142,542,000
Total	147,588,000	143,504,000
Commercial Real Estate Portfolio Segment [Member]
Individually evaluated for impairment	51,000	23,000
Collectively evaluated for impairment	3,418,000	4,086,000
Total	3,469,000	4,109,000	3,818,000	3,537,000
Individually evaluated for impairment	8,773,000	12,575,000
Collectively evaluated for impairment	312,270,000	296,803,000
Total	321,043,000	309,378,000
Commercial Non Real Estate Segment [Member]
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	1,485,000	655,000
Total	1,485,000	655,000	941,000	1,475,000
Individually evaluated for impairment	315,000	1,091,000
Collectively evaluated for impairment	41,412,000	36,480,000
Total	41,727,000	37,571,000
Public Sector and IDA Portfolio Segment[Member]
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	381,000	436,000
Total	381,000	436,000	486,000	327,000
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	47,046,000	51,335,000
Total	47,046,000	51,335,000
Consumer Non Real Estate Portfolio Segment [Member]
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	555,000	627,000
Total	555,000	627,000	514,000	602,000
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	32,027,000	29,845,000
Total	32,027,000	29,845,000
Unallocated Financing Receivables [Member]
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	14,000	28,000
Total	14,000	28,000	59,000	48,000
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	0	0
Total	0	0
Individually evaluated for impairment	71,000	45,000
Collectively evaluated for impairment	8,124,000	8,252,000
Total	8,195,000	8,297,000	$ 8,131,000	$ 8,263,000
Individually evaluated for impairment	10,700,000	15,346,000
Collectively evaluated for impairment	621,065,000	604,538,000
Total	$ 631,765,000	$ 619,884,000