Note 4 - Loans Leases Receivable - Impaired Loans Leases (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Recorded investment with no specific allowance recorded	$ 7,117,268	$ 4,637,593	$ 3,932,541
Unpaid principal balance with no specific allowance recorded	7,202,484	4,880,273	4,402,147
Average recorded investment with no specific allowance recorded	6,354,341	7,510,986	6,656,069
Interest income recognized with no specific allowance recorded	216,413	74,587	25,070
Interest income recognized for cash payments received with no specific allowance recorded	216,413	74,587	25,070
Recorded investment with specific allowance recorded	11,236,897	15,434,506	7,090,846
Unpaid principal balance with specific allowance recorded	11,240,836	15,512,479	7,106,685
Related allowance	3,043,319	3,642,968	3,304,287
Average recorded investment with specific allowance recorded	10,512,445	5,870,942	6,383,114
Interest income recognized with specific allowance recorded	218,621	66,247	13,606
Interest income recognized for cash payments received with specific allowance recorded	218,621	66,247	13,606
Recorded investment	18,354,163	20,072,099	11,023,387
Unpaid principal balance	18,443,318	20,392,752	11,508,832
Average recorded investment	16,866,786	13,381,928	13,039,183
Interest income recognized	435,034	140,834	38,676
Interest income recognized for cash payments received	435,034	140,834	38,676
Commercial Portfolio Segment [Member]
Recorded investment with no specific allowance recorded	1,634,269	841,895	234,636
Unpaid principal balance with no specific allowance recorded	1,644,706	951,600	346,072
Average recorded investment with no specific allowance recorded	1,406,310	2,858,343	380,495
Interest income recognized with no specific allowance recorded	71,183	16,748	7,436
Interest income recognized for cash payments received with no specific allowance recorded	71,183	16,748	7,436
Recorded investment with specific allowance recorded	4,613,940	8,094,556	5,051,846
Unpaid principal balance with specific allowance recorded	4,617,879	8,098,395	5,055,685
Related allowance	715,627	1,771,537	2,592,270
Average recorded investment with specific allowance recorded	4,584,142	2,959,495	4,811,046
Interest income recognized with specific allowance recorded	203,221	17,742
Interest income recognized for cash payments received with specific allowance recorded	203,221	17,742
Recorded investment	6,248,209	8,936,451	5,286,482
Unpaid principal balance	6,262,585	9,049,995	5,401,757
Average recorded investment	5,990,452	5,817,838	5,191,541
Interest income recognized	274,404	34,490	7,436
Interest income recognized for cash payments received	274,404	34,490	7,436
Commercial Real Estate Portfolio Segment [Member] | Owner Occupied Commercial Real Estate Loans [Member]
Recorded investment with no specific allowance recorded	289,261		256,761
Unpaid principal balance with no specific allowance recorded	289,261	93,774	350,535
Average recorded investment with no specific allowance recorded	79,317	312,242	447,144
Interest income recognized with no specific allowance recorded	11,902
Interest income recognized for cash payments received with no specific allowance recorded	11,902
Recorded investment with specific allowance recorded	151,962	322,148
Unpaid principal balance with specific allowance recorded	151,962	322,148
Related allowance	48,462	57,398
Average recorded investment with specific allowance recorded	221,260	385,269
Interest income recognized with specific allowance recorded
Interest income recognized for cash payments received with specific allowance recorded
Recorded investment	441,222	322,148	256,761
Unpaid principal balance	441,222	415,922	350,535
Average recorded investment	300,577	697,511	447,144
Interest income recognized	11,902
Interest income recognized for cash payments received	11,902
Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Recorded investment with no specific allowance recorded
Unpaid principal balance with no specific allowance recorded			228,818
Average recorded investment with no specific allowance recorded			117,406
Interest income recognized with no specific allowance recorded
Interest income recognized for cash payments received with no specific allowance recorded
Recorded investment with specific allowance recorded	4,844,312	4,353,817	193,804
Unpaid principal balance with specific allowance recorded	4,844,312	4,353,819	205,804
Related allowance	1,379,235	577,611	76,934
Average recorded investment with specific allowance recorded	4,447,831	1,022,930	195,986
Interest income recognized with specific allowance recorded
Interest income recognized for cash payments received with specific allowance recorded
Recorded investment	4,844,312	4,353,817	193,804
Unpaid principal balance	4,844,312	4,353,819	434,622
Average recorded investment	4,447,831	1,022,930	313,392
Interest income recognized
Interest income recognized for cash payments received
Commercial Real Estate Portfolio Segment [Member] | Other Non-owner Occupied Commercial Real Estate Loans [Member]
Recorded investment with no specific allowance recorded	1,171,565	1,196,549	1,578,470
Unpaid principal balance with no specific allowance recorded	1,171,565	1,196,549	1,578,470
Average recorded investment with no specific allowance recorded	1,176,738	1,322,654	2,953,888
Interest income recognized with no specific allowance recorded
Interest income recognized for cash payments received with no specific allowance recorded
Recorded investment with specific allowance recorded	72,163	239,600
Unpaid principal balance with specific allowance recorded	72,163	239,600
Related allowance	1,763	58,910
Average recorded investment with specific allowance recorded	44,667	47,920
Interest income recognized with specific allowance recorded
Interest income recognized for cash payments received with specific allowance recorded
Recorded investment	1,243,728	1,436,149	1,578,470
Unpaid principal balance	1,243,728	1,436,149	1,578,470
Average recorded investment	1,221,405	1,370,574	2,953,888
Interest income recognized
Interest income recognized for cash payments received
Finance Leases Portfolio Segment [Member]
Recorded investment with no specific allowance recorded	2,944,540	1,690,121	871,884
Unpaid principal balance with no specific allowance recorded	2,944,540	1,690,121	871,884
Average recorded investment with no specific allowance recorded	2,879,695	1,731,982	892,281
Interest income recognized with no specific allowance recorded	132,167	43,461	4,142
Interest income recognized for cash payments received with no specific allowance recorded	132,167	43,461	4,142
Recorded investment with specific allowance recorded	724,953	1,566,143	829,457
Unpaid principal balance with specific allowance recorded	724,953	1,566,143	829,457
Related allowance	504,469	848,919	306,193
Average recorded investment with specific allowance recorded	625,107	841,733	474,458
Interest income recognized with specific allowance recorded		36,303
Interest income recognized for cash payments received with specific allowance recorded		36,303
Recorded investment	3,669,492	3,256,264	1,701,341
Unpaid principal balance	3,669,492	3,256,264	1,701,341
Average recorded investment	3,504,802	2,573,715	1,366,739
Interest income recognized	132,167	79,764	4,142
Interest income recognized for cash payments received	132,167	79,764	4,142
Residential Portfolio Segment [Member]
Recorded investment with no specific allowance recorded	943,388	853,294	613,486
Unpaid principal balance with no specific allowance recorded	1,018,167	892,495	649,064
Average recorded investment with no specific allowance recorded	685,807	964,590	1,047,001
Interest income recognized with no specific allowance recorded	1,161	9,903	3,929
Interest income recognized for cash payments received with no specific allowance recorded	1,161	9,903	3,929
Recorded investment with specific allowance recorded	761,458	807,886	805,301
Unpaid principal balance with specific allowance recorded	761,458	882,018	805,301
Related allowance	355,167	289,112	185,801
Average recorded investment with specific allowance recorded	549,286	573,211	712,085
Interest income recognized with specific allowance recorded	14,990	11,675	7,913
Interest income recognized for cash payments received with specific allowance recorded	14,990	11,675	7,913
Recorded investment	1,704,846	1,661,180	1,418,787
Unpaid principal balance	1,779,625	1,774,513	1,454,365
Average recorded investment	1,235,093	1,537,801	1,759,086
Interest income recognized	16,151	21,578	11,842
Interest income recognized for cash payments received	16,151	21,578	11,842
Consumer Portfolio Segment [Member]
Recorded investment with no specific allowance recorded	134,245	55,734	377,304
Unpaid principal balance with no specific allowance recorded	134,245	55,734	377,304
Average recorded investment with no specific allowance recorded	126,474	321,175	817,854
Interest income recognized with no specific allowance recorded		4,475	9,563
Interest income recognized for cash payments received with no specific allowance recorded		4,475	9,563
Recorded investment with specific allowance recorded	68,109	50,356	210,438
Unpaid principal balance with specific allowance recorded	68,109	50,356	210,438
Related allowance	38,596	39,481	143,089
Average recorded investment with specific allowance recorded	40,152	40,384	189,539
Interest income recognized with specific allowance recorded	410	527	5,693
Interest income recognized for cash payments received with specific allowance recorded	410	527	5,693
Recorded investment	202,354	106,090	587,742
Unpaid principal balance	202,354	106,090	587,742
Average recorded investment	166,626	361,559	1,007,393
Interest income recognized	410	5,002	15,256
Interest income recognized for cash payments received	$ 410	$ 5,002	$ 15,256