Note 3 - Loans Leases Receivable - Allowance for Estimated Losses on Loans Leases (Details) - USD ($)		3 Months Ended
		Mar. 31, 2018		Mar. 31, 2017	Mar. 31, 2018		Dec. 31, 2017
Balance		$ 34,355,728		$ 30,757,448
Provision for loan/lease losses		2,539,839		2,105,109
Loans/leases charged off		(436,458)		(892,626)
Recoveries on loans/leases previously charged off		73,493		89,219
Balance		36,532,602		32,059,150
Allowance for impaired loans/leases					$ 3,227,366		$ 3,043,319
Allowance for nonimpaired loans/leases					33,305,236		31,312,409
Less allowance for estimated losses on loans/leases		36,532,602		30,757,448	36,532,602		34,355,728
Impaired loans/leases					17,918,781		18,354,163
Nonimpaired loans/leases					3,028,880,495		2,938,359,330
Loans					$ 3,046,799,276		$ 2,956,713,493
Allowance as a percentage of impaired loans/leases					18.01%		16.58%
Allowance as a percentage of nonimpaired loans/leases					1.10%		1.07%
Total allowance as a percentage of total loans/leases					1.20%		1.16%
Commercial Portfolio Segment [Member]
Balance		14,323,036		12,545,110
Provision for loan/lease losses		808,161		593,359
Loans/leases charged off		(95,499)		(218,273)
Recoveries on loans/leases previously charged off		29,547		33,894
Balance		15,065,245		12,954,090
Allowance for impaired loans/leases					$ 567,321		$ 715,627
Allowance for nonimpaired loans/leases					14,497,924		13,607,409
Less allowance for estimated losses on loans/leases		14,323,036		12,545,110	15,065,245		14,323,036
Impaired loans/leases					6,010,688		6,248,209
Nonimpaired loans/leases					1,195,074,937		1,128,268,106
Loans	[1]				$ 1,201,085,625		$ 1,134,516,315
Allowance as a percentage of impaired loans/leases					9.44%		11.45%
Allowance as a percentage of nonimpaired loans/leases					1.21%		1.21%
Total allowance as a percentage of total loans/leases					1.25%		1.26%
Commercial Real Estate Portfolio Segment [Member]
Balance		13,962,688		11,670,609
Provision for loan/lease losses		965,383		966,271
Loans/leases charged off
Recoveries on loans/leases previously charged off		9,949		6,386
Balance		14,938,020		12,643,266
Allowance for impaired loans/leases					$ 1,670,897		$ 1,429,460
Allowance for nonimpaired loans/leases					13,267,123		12,533,228
Less allowance for estimated losses on loans/leases		13,962,688		11,670,609	14,938,020		13,962,688
Impaired loans/leases					7,094,483		6,529,262
Nonimpaired loans/leases					1,350,608,903		1,296,962,620
Loans					$ 1,357,703,386		$ 1,303,491,882
Allowance as a percentage of impaired loans/leases					23.55%		21.89%
Allowance as a percentage of nonimpaired loans/leases					0.98%		0.97%
Total allowance as a percentage of total loans/leases					1.10%		1.07%
Finance Leases Portfolio Segment [Member]
Balance		2,382,098	[1]	3,111,898
Provision for loan/lease losses		604,783		505,015
Loans/leases charged off		(283,887)		(658,684)
Recoveries on loans/leases previously charged off		27,307		20,031
Balance		2,730,301	[1]	2,978,260
Allowance for impaired loans/leases					$ 628,379		$ 504,469
Allowance for nonimpaired loans/leases					2,101,922		1,877,629
Less allowance for estimated losses on loans/leases		2,730,301	[1]	3,111,898	2,730,301	[1]	2,382,098	[1]
Impaired loans/leases					2,975,596		3,669,492
Nonimpaired loans/leases					134,638,869		137,778,740
Loans	[1],[2]				$ 137,614,465		$ 141,448,232
Allowance as a percentage of impaired loans/leases					21.12%		13.75%
Allowance as a percentage of nonimpaired loans/leases					1.56%		1.36%
Total allowance as a percentage of total loans/leases					1.98%		1.68%
Residential Portfolio Segment [Member]
Balance		2,466,431		2,342,344
Provision for loan/lease losses		(39,337)		43,520
Loans/leases charged off		(52,325)		(13,623)
Recoveries on loans/leases previously charged off		450		3,623
Balance		2,375,219		2,375,864
Allowance for impaired loans/leases					$ 248,592		$ 355,167
Allowance for nonimpaired loans/leases					2,126,627		2,111,264
Less allowance for estimated losses on loans/leases		2,466,431		2,342,344	2,375,219		2,466,431
Impaired loans/leases					1,556,817		1,704,846
Nonimpaired loans/leases					252,927,414		256,941,419
Loans	[3]				$ 254,484,231	[2]	$ 258,646,265
Allowance as a percentage of impaired loans/leases					15.97%		20.83%
Allowance as a percentage of nonimpaired loans/leases					0.84%		0.82%
Total allowance as a percentage of total loans/leases					0.93%		0.95%
Consumer Portfolio Segment [Member]
Balance		1,221,475		1,087,487
Provision for loan/lease losses		200,849		(3,056)
Loans/leases charged off		(4,747)		(2,046)
Recoveries on loans/leases previously charged off		6,240		25,285
Balance		1,423,817		1,107,670
Allowance for impaired loans/leases					$ 112,177		$ 38,596
Allowance for nonimpaired loans/leases					1,311,640		1,182,879
Less allowance for estimated losses on loans/leases		$ 1,221,475		$ 1,087,487	1,423,817		1,221,475
Impaired loans/leases					281,197		202,354
Nonimpaired loans/leases					95,630,372		118,408,445
Loans	[2]				$ 95,911,569		$ 118,610,799
Allowance as a percentage of impaired loans/leases					39.89%		19.07%
Allowance as a percentage of nonimpaired loans/leases					1.37%		1.00%
Total allowance as a percentage of total loans/leases					1.48%		1.03%

[1] Includes equipment financing agreements outstanding at m2, totaling $78,911,791 and $66,758,397 as of March 31, 2018 and December 31, 2017, respectively.

[2] Performing = loans/leases accruing and less than 90 days past due. Nonperforming = loans/leases on nonaccrual, accruing loans/leases that are greater than or equal to 90 days past due, and accruing TDRs.

[3] Includes residential real estate loans held for sale totaling $279,750 and $645,001 as of March 31, 2018, and December 31, 2017, respectively.