Note 5 - Allowance for Credit Losses (Details) - Allowance for Loan and Lease Losses by Loan Category - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Collectively evaluated for impairment:
Allowance for loan and lease losses	$ 7,809,700	$ 7,873,790
Loans charged off	(702,557)	(1,316,082)
Allowance for loan losses, recoveries	249,110	126,585
Allowance for loan losses, provisions	800,000	1,100,000
Allowance for loan and lease losses	8,202,710	7,809,700
Loans held for investment	607,865,000	481,272,000
Total Collectively Evaluated [Member]
Collectively evaluated for impairment:
Loans held for investment	592,045,000	461,000,000
Total Individually Evaluated [Member]
Collectively evaluated for impairment:
Loans held for investment	15,820,000	20,272,000
Residential Portfolio Segment [Member]
Collectively evaluated for impairment:
Loans held for investment	72,320,000	66,857,000
Residential Portfolio Segment [Member] | Real Estate Loan [Member]
Collectively evaluated for impairment:
Loans charged off	(301,000)	(33,000)
Allowance for loan losses, recoveries	1,000	0
Loans held for investment	68,229,000	64,647,000
Residential Portfolio Segment [Member] | Construction Loans [Member]
Collectively evaluated for impairment:
Loans held for investment	3,934,000	1,382,000
Residential Portfolio Segment [Member] | Lots and Raw Land [Member]
Collectively evaluated for impairment:
Loans held for investment	157,000	828,000
Residential Portfolio Segment [Member] | Total Collectively Evaluated [Member] | Real Estate Loan [Member]
Collectively evaluated for impairment:
Loans held for investment	67,142,000	62,907,000
Residential Portfolio Segment [Member] | Total Collectively Evaluated [Member] | Construction Loans [Member]
Collectively evaluated for impairment:
Loans held for investment	3,934,000	1,382,000
Residential Portfolio Segment [Member] | Total Collectively Evaluated [Member] | Lots and Raw Land [Member]
Collectively evaluated for impairment:
Loans held for investment	157,000	828,000
Residential Portfolio Segment [Member] | Total Individually Evaluated [Member] | Real Estate Loan [Member]
Collectively evaluated for impairment:
Loans held for investment	1,087,000	1,740,000
Commercial Portfolio Segment [Member]
Collectively evaluated for impairment:
Loans held for investment	472,688,000	351,719,000
Commercial Portfolio Segment [Member] | Real Estate Loan [Member]
Collectively evaluated for impairment:
Loans charged off	(172,000)	(738,000)
Allowance for loan losses, recoveries	83,000	42,000
Loans held for investment	338,714,000	255,800,000
Commercial Portfolio Segment [Member] | Construction Loans [Member]
Collectively evaluated for impairment:
Loans charged off	0	0
Allowance for loan losses, recoveries	0	3,000
Loans held for investment	42,987,000	27,646,000
Commercial Portfolio Segment [Member] | Lots and Raw Land [Member]
Collectively evaluated for impairment:
Loans charged off	(33,000)	(110,000)
Allowance for loan losses, recoveries	4,000	8,000
Loans held for investment	28,271,000	27,502,000
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Collectively evaluated for impairment:
Loans charged off	0	(53,000)
Allowance for loan losses, recoveries	0	9,000
Loans held for investment	45,481,000	28,379,000
Commercial Portfolio Segment [Member] | Lease Receivables [Member]
Collectively evaluated for impairment:
Loans charged off	0	(3,000)
Loans held for investment	17,235,000	12,392,000
Commercial Portfolio Segment [Member] | Total Collectively Evaluated [Member] | Real Estate Loan [Member]
Collectively evaluated for impairment:
Loans held for investment	328,372,000	241,939,000
Commercial Portfolio Segment [Member] | Total Collectively Evaluated [Member] | Construction Loans [Member]
Collectively evaluated for impairment:
Loans held for investment	42,413,000	27,543,000
Commercial Portfolio Segment [Member] | Total Collectively Evaluated [Member] | Lots and Raw Land [Member]
Collectively evaluated for impairment:
Loans held for investment	25,655,000	24,135,000
Commercial Portfolio Segment [Member] | Total Collectively Evaluated [Member] | Commercial and Industrial [Member]
Collectively evaluated for impairment:
Loans held for investment	45,425,000	28,333,000
Commercial Portfolio Segment [Member] | Total Collectively Evaluated [Member] | Lease Receivables [Member]
Collectively evaluated for impairment:
Loans held for investment	17,235,000	12,392,000
Commercial Portfolio Segment [Member] | Total Individually Evaluated [Member] | Real Estate Loan [Member]
Collectively evaluated for impairment:
Loans held for investment	10,342,000	13,861,000
Commercial Portfolio Segment [Member] | Total Individually Evaluated [Member] | Construction Loans [Member]
Collectively evaluated for impairment:
Loans held for investment	574,000	103,000
Commercial Portfolio Segment [Member] | Total Individually Evaluated [Member] | Lots and Raw Land [Member]
Collectively evaluated for impairment:
Loans held for investment	2,616,000	3,367,000
Commercial Portfolio Segment [Member] | Total Individually Evaluated [Member] | Commercial and Industrial [Member]
Collectively evaluated for impairment:
Loans held for investment	56,000	46,000
Consumer Portfolio Segment [Member]
Collectively evaluated for impairment:
Loans held for investment	62,857,000	62,696,000
Consumer Portfolio Segment [Member] | Real Estate Loan [Member]
Collectively evaluated for impairment:
Loans charged off	(85,000)	(54,000)
Allowance for loan losses, recoveries	18,000	30,000
Loans held for investment	17,239,000	18,863,000
Consumer Portfolio Segment [Member] | Construction Loans [Member]
Collectively evaluated for impairment:
Loans held for investment	196,000	1,412,000
Consumer Portfolio Segment [Member] | Lots and Raw Land [Member]
Collectively evaluated for impairment:
Loans charged off	(85,000)	(260,000)
Allowance for loan losses, recoveries	8,000	0
Loans held for investment	9,643,000	10,430,000
Consumer Portfolio Segment [Member] | Home Equity Loan [Member]
Collectively evaluated for impairment:
Loans charged off	(13,000)	(13,000)
Allowance for loan losses, recoveries	36,000	14,000
Loans held for investment	29,709,000	28,059,000
Consumer Portfolio Segment [Member] | Other Loans [Member]
Collectively evaluated for impairment:
Loans charged off	(13,000)	(52,000)
Allowance for loan losses, recoveries	99,000	21,000
Loans held for investment	6,070,000	3,932,000
Consumer Portfolio Segment [Member] | Total Collectively Evaluated [Member] | Real Estate Loan [Member]
Collectively evaluated for impairment:
Loans held for investment	16,959,000	18,539,000
Consumer Portfolio Segment [Member] | Total Collectively Evaluated [Member] | Construction Loans [Member]
Collectively evaluated for impairment:
Loans held for investment	196,000	1,412,000
Consumer Portfolio Segment [Member] | Total Collectively Evaluated [Member] | Lots and Raw Land [Member]
Collectively evaluated for impairment:
Loans held for investment	8,870,000	9,728,000
Consumer Portfolio Segment [Member] | Total Collectively Evaluated [Member] | Home Equity Loan [Member]
Collectively evaluated for impairment:
Loans held for investment	29,659,000	27,976,000
Consumer Portfolio Segment [Member] | Total Collectively Evaluated [Member] | Other Loans [Member]
Collectively evaluated for impairment:
Loans held for investment	6,028,000	3,886,000
Consumer Portfolio Segment [Member] | Total Individually Evaluated [Member] | Real Estate Loan [Member]
Collectively evaluated for impairment:
Loans held for investment	280,000	324,000
Consumer Portfolio Segment [Member] | Total Individually Evaluated [Member] | Lots and Raw Land [Member]
Collectively evaluated for impairment:
Loans held for investment	773,000	702,000
Consumer Portfolio Segment [Member] | Total Individually Evaluated [Member] | Home Equity Loan [Member]
Collectively evaluated for impairment:
Loans held for investment	50,000	83,000
Consumer Portfolio Segment [Member] | Total Individually Evaluated [Member] | Other Loans [Member]
Collectively evaluated for impairment:
Loans held for investment	42,000	46,000
Allowance for Loans and Leases Receivable [Member]
Collectively evaluated for impairment:
Allowance for loan and lease losses	7,520,000	7,609,000
Loans charged off	(702,000)	(1,316,000)
Allowance for loan losses, recoveries	249,000	127,000
Allowance for loan losses, provisions	800,000	1,100,000
Allowance for loan and lease losses	7,867,000	7,520,000
Allowance for Loans and Leases Receivable [Member] | Total Collectively Evaluated [Member]
Collectively evaluated for impairment:
Allowance for loan and lease losses	6,728,000	6,946,000
Loans charged off	(145,000)	(472,000)
Allowance for loan losses, recoveries	170,000	105,000
Allowance for loan losses, provisions	496,000	149,000
Allowance for loan and lease losses	7,249,000	6,728,000
Allowance for Loans and Leases Receivable [Member] | Total Individually Evaluated [Member]
Collectively evaluated for impairment:
Allowance for loan and lease losses	792,000	663,000
Loans charged off	(557,000)	(844,000)
Allowance for loan losses, recoveries	79,000	22,000
Allowance for loan losses, provisions	304,000	951,000
Allowance for loan and lease losses	618,000	792,000
Allowance for Loans and Leases Receivable [Member] | Residential Portfolio Segment [Member] | Total Collectively Evaluated [Member] | Real Estate Loan [Member]
Collectively evaluated for impairment:
Allowance for loan and lease losses	982,000	903,000
Loans charged off	(116,000)	(33,000)
Allowance for loan losses, recoveries	0	0
Allowance for loan losses, provisions	(136,000)	112,000
Allowance for loan and lease losses	730,000	982,000
Allowance for Loans and Leases Receivable [Member] | Residential Portfolio Segment [Member] | Total Collectively Evaluated [Member] | Construction Loans [Member]
Collectively evaluated for impairment:
Allowance for loan and lease losses	17,000	17,000
Loans charged off	0	0
Allowance for loan losses, recoveries	0	0
Allowance for loan losses, provisions	30,000	0
Allowance for loan and lease losses	47,000	17,000
Allowance for Loans and Leases Receivable [Member] | Residential Portfolio Segment [Member] | Total Collectively Evaluated [Member] | Lots and Raw Land [Member]
Collectively evaluated for impairment:
Allowance for loan and lease losses	11,000	13,000
Loans charged off	0	0
Allowance for loan losses, recoveries	0	0
Allowance for loan losses, provisions	(9,000)	(2,000)
Allowance for loan and lease losses	2,000	11,000
Allowance for Loans and Leases Receivable [Member] | Residential Portfolio Segment [Member] | Total Individually Evaluated [Member] | Real Estate Loan [Member]
Collectively evaluated for impairment:
Allowance for loan and lease losses	185,000	0
Loans charged off	(185,000)	0
Allowance for loan losses, recoveries	1,000	0
Allowance for loan losses, provisions	(1,000)	185,000
Allowance for loan and lease losses	0	185,000
Allowance for Loans and Leases Receivable [Member] | Commercial Portfolio Segment [Member] | Total Collectively Evaluated [Member] | Real Estate Loan [Member]
Collectively evaluated for impairment:
Allowance for loan and lease losses	3,516,000	3,647,000
Loans charged off	(3,000)	(174,000)
Allowance for loan losses, recoveries	48,000	36,000
Allowance for loan losses, provisions	504,000	7,000
Allowance for loan and lease losses	4,065,000	3,516,000
Allowance for Loans and Leases Receivable [Member] | Commercial Portfolio Segment [Member] | Total Collectively Evaluated [Member] | Construction Loans [Member]
Collectively evaluated for impairment:
Allowance for loan and lease losses	375,000	343,000
Loans charged off	0	0
Allowance for loan losses, recoveries	0	2,000
Allowance for loan losses, provisions	143,000	30,000
Allowance for loan and lease losses	518,000	375,000
Allowance for Loans and Leases Receivable [Member] | Commercial Portfolio Segment [Member] | Total Collectively Evaluated [Member] | Lots and Raw Land [Member]
Collectively evaluated for impairment:
Allowance for loan and lease losses	377,000	415,000
Loans charged off	0	0
Allowance for loan losses, recoveries	0	0
Allowance for loan losses, provisions	(74,000)	(38,000)
Allowance for loan and lease losses	303,000	377,000
Allowance for Loans and Leases Receivable [Member] | Commercial Portfolio Segment [Member] | Total Collectively Evaluated [Member] | Commercial and Industrial [Member]
Collectively evaluated for impairment:
Allowance for loan and lease losses	400,000	430,000
Loans charged off	0	(4,000)
Allowance for loan losses, recoveries	4,000	9,000
Allowance for loan losses, provisions	237,000	(35,000)
Allowance for loan and lease losses	641,000	400,000
Allowance for Loans and Leases Receivable [Member] | Commercial Portfolio Segment [Member] | Total Collectively Evaluated [Member] | Lease Receivables [Member]
Collectively evaluated for impairment:
Allowance for loan and lease losses	172,000	113,000
Loans charged off	0	(3,000)
Allowance for loan losses, recoveries	0	0
Allowance for loan losses, provisions	24,000	62,000
Allowance for loan and lease losses	196,000	172,000
Allowance for Loans and Leases Receivable [Member] | Commercial Portfolio Segment [Member] | Total Individually Evaluated [Member] | Real Estate Loan [Member]
Collectively evaluated for impairment:
Allowance for loan and lease losses	167,000	510,000
Loans charged off	(169,000)	(564,000)
Allowance for loan losses, recoveries	35,000	6,000
Allowance for loan losses, provisions	(33,000)	215,000
Allowance for loan and lease losses	0	167,000
Allowance for Loans and Leases Receivable [Member] | Commercial Portfolio Segment [Member] | Total Individually Evaluated [Member] | Construction Loans [Member]
Collectively evaluated for impairment:
Allowance for loan and lease losses	0	0
Loans charged off	0	0
Allowance for loan losses, recoveries	0	1,000
Allowance for loan losses, provisions	0	(1,000)
Allowance for loan and lease losses	0	0
Allowance for Loans and Leases Receivable [Member] | Commercial Portfolio Segment [Member] | Total Individually Evaluated [Member] | Lots and Raw Land [Member]
Collectively evaluated for impairment:
Allowance for loan and lease losses	251,000	0
Loans charged off	(33,000)	(110,000)
Allowance for loan losses, recoveries	0	8,000
Allowance for loan losses, provisions	147,000	353,000
Allowance for loan and lease losses	365,000	251,000
Allowance for Loans and Leases Receivable [Member] | Commercial Portfolio Segment [Member] | Total Individually Evaluated [Member] | Commercial and Industrial [Member]
Collectively evaluated for impairment:
Allowance for loan and lease losses	0	23,000
Loans charged off	0	(49,000)
Allowance for loan losses, recoveries	0	0
Allowance for loan losses, provisions	14,000	26,000
Allowance for loan and lease losses	14,000	0
Allowance for Loans and Leases Receivable [Member] | Consumer Portfolio Segment [Member] | Total Collectively Evaluated [Member] | Real Estate Loan [Member]
Collectively evaluated for impairment:
Allowance for loan and lease losses	250,000	316,000
Loans charged off	0	0
Allowance for loan losses, recoveries	18,000	30,000
Allowance for loan losses, provisions	(70,000)	(96,000)
Allowance for loan and lease losses	198,000	250,000
Allowance for Loans and Leases Receivable [Member] | Consumer Portfolio Segment [Member] | Total Collectively Evaluated [Member] | Construction Loans [Member]
Collectively evaluated for impairment:
Allowance for loan and lease losses	19,000	23,000
Loans charged off	0	0
Allowance for loan losses, recoveries	0	0
Allowance for loan losses, provisions	(17,000)	(4,000)
Allowance for loan and lease losses	2,000	19,000
Allowance for Loans and Leases Receivable [Member] | Consumer Portfolio Segment [Member] | Total Collectively Evaluated [Member] | Lots and Raw Land [Member]
Collectively evaluated for impairment:
Allowance for loan and lease losses	152,000	203,000
Loans charged off	0	(232,000)
Allowance for loan losses, recoveries	0	0
Allowance for loan losses, provisions	(27,000)	181,000
Allowance for loan and lease losses	125,000	152,000
Allowance for Loans and Leases Receivable [Member] | Consumer Portfolio Segment [Member] | Total Collectively Evaluated [Member] | Home Equity Loan [Member]
Collectively evaluated for impairment:
Allowance for loan and lease losses	405,000	463,000
Loans charged off	(13,000)	(12,000)
Allowance for loan losses, recoveries	1,000	7,000
Allowance for loan losses, provisions	(42,000)	(53,000)
Allowance for loan and lease losses	351,000	405,000
Allowance for Loans and Leases Receivable [Member] | Consumer Portfolio Segment [Member] | Total Collectively Evaluated [Member] | Other Loans [Member]
Collectively evaluated for impairment:
Allowance for loan and lease losses	52,000	60,000
Loans charged off	(13,000)	(14,000)
Allowance for loan losses, recoveries	99,000	21,000
Allowance for loan losses, provisions	(67,000)	(15,000)
Allowance for loan and lease losses	71,000	52,000
Allowance for Loans and Leases Receivable [Member] | Consumer Portfolio Segment [Member] | Total Individually Evaluated [Member] | Real Estate Loan [Member]
Collectively evaluated for impairment:
Allowance for loan and lease losses	19,000	25,000
Loans charged off	(85,000)	(54,000)
Allowance for loan losses, recoveries	0	0
Allowance for loan losses, provisions	96,000	48,000
Allowance for loan and lease losses	30,000	19,000
Allowance for Loans and Leases Receivable [Member] | Consumer Portfolio Segment [Member] | Total Individually Evaluated [Member] | Lots and Raw Land [Member]
Collectively evaluated for impairment:
Allowance for loan and lease losses	165,000	105,000
Loans charged off	(85,000)	(28,000)
Allowance for loan losses, recoveries	8,000	0
Allowance for loan losses, provisions	121,000	88,000
Allowance for loan and lease losses	209,000	165,000
Allowance for Loans and Leases Receivable [Member] | Consumer Portfolio Segment [Member] | Total Individually Evaluated [Member] | Home Equity Loan [Member]
Collectively evaluated for impairment:
Allowance for loan and lease losses	5,000	0
Loans charged off	0	(1,000)
Allowance for loan losses, recoveries	35,000	7,000
Allowance for loan losses, provisions	(40,000)	(1,000)
Allowance for loan and lease losses	0	5,000
Allowance for Loans and Leases Receivable [Member] | Consumer Portfolio Segment [Member] | Total Individually Evaluated [Member] | Other Loans [Member]
Collectively evaluated for impairment:
Allowance for loan and lease losses	0	0
Loans charged off	0	(38,000)
Allowance for loan losses, recoveries	0	0
Allowance for loan losses, provisions	0	38,000
Allowance for loan and lease losses	$ 0	$ 0