Note 3 - Loans Leases Receivable - Aging of the Loan Lease Portfolio (Details) - USD ($)		Mar. 31, 2018		Dec. 31, 2017
Current		$ 3,026,862,570		$ 2,929,430,446
Accruing Past Due 90 Days or More		40,940		88,671
Financing Receivable, Recorded Investment, Nonaccrual Status		12,758,985		11,441,234
Loans and Leases Receivable, Net of Deferred Income, Total		$ 3,046,799,276		$ 2,956,713,493
Current as a percentage of total loan/lease portfolio		99.34%		99.08%
Accruing past due 90 days or more as a percentage of total loan/lease portfolio		0.00%		0.00%
Nonaccrual Loans/Leases as a percentage of total loan/lease portfolio		0.42%		0.39%
Loans and leases as a percentage of total loan/lease portfolio		100.00%		100.00%
Financing Receivables, 30 to 59 Days Past Due [Member]
Past Due		$ 5,708,921		$ 14,795,578
Past due as a percentage of total loan/lease portfolio		0.19%		0.50%
Financing Receivables, 60 to 89 Days Past Due [Member]
Past Due		$ 1,427,860		$ 957,563
Past due as a percentage of total loan/lease portfolio		0.05%		0.03%
Commercial Portfolio Segment [Member]
Current		$ 1,197,675,583		$ 1,124,734,486
Accruing Past Due 90 Days or More		36,162
Financing Receivable, Recorded Investment, Nonaccrual Status		1,448,542		1,231,353	[1]
Loans and Leases Receivable, Net of Deferred Income, Total	[2]	1,201,085,625		1,134,516,315
Commercial Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Past Due		1,714,614		8,306,829
Commercial Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Past Due		210,724		243,647
Commercial Real Estate Portfolio Segment [Member]
Loans and Leases Receivable, Net of Deferred Income, Total		1,357,703,386		1,303,491,882
Commercial Real Estate Portfolio Segment [Member] | Owner Occupied Commercial Real Estate Loans [Member]
Current		346,524,727		331,868,142
Accruing Past Due 90 Days or More
Financing Receivable, Recorded Investment, Nonaccrual Status		329,313		333,900	[1]
Loans and Leases Receivable, Net of Deferred Income, Total		346,996,627		332,742,477
Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Current		168,928,348		181,558,092
Accruing Past Due 90 Days or More
Financing Receivable, Recorded Investment, Nonaccrual Status		1,852,196		4,844,312	[1]
Loans and Leases Receivable, Net of Deferred Income, Total		171,404,628		186,402,404
Commercial Real Estate Portfolio Segment [Member] | Other Non-owner Occupied Commercial Real Estate Loans [Member]
Current		834,328,826		782,526,249
Accruing Past Due 90 Days or More
Financing Receivable, Recorded Investment, Nonaccrual Status		4,868,082		1,243,728	[1]
Loans and Leases Receivable, Net of Deferred Income, Total		839,302,131		784,347,000
Commercial Real Estate Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Owner Occupied Commercial Real Estate Loans [Member]
Past Due		142,587		540,435
Commercial Real Estate Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Construction Loans [Member]
Past Due		55,561
Commercial Real Estate Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Other Non-owner Occupied Commercial Real Estate Loans [Member]
Past Due		105,223		572,877
Commercial Real Estate Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Owner Occupied Commercial Real Estate Loans [Member]
Past Due
Commercial Real Estate Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Construction Loans [Member]
Past Due		568,523
Commercial Real Estate Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Other Non-owner Occupied Commercial Real Estate Loans [Member]
Past Due				4,146
Finance Leases Portfolio Segment [Member]
Current		133,012,415		137,708,397
Accruing Past Due 90 Days or More
Financing Receivable, Recorded Investment, Nonaccrual Status		2,806,398		2,175,044	[1]
Loans and Leases Receivable, Net of Deferred Income, Total	[2],[3]	137,614,465		141,448,232
Finance Leases Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Past Due		1,196,302		1,305,191
Finance Leases Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Past Due		599,350		259,600
Residential Portfolio Segment [Member]
Current		250,956,900		253,261,821
Accruing Past Due 90 Days or More				74,519
Financing Receivable, Recorded Investment, Nonaccrual Status		1,187,267		1,363,806	[1]
Loans and Leases Receivable, Net of Deferred Income, Total	[4]	254,484,231	[3]	258,646,265
Residential Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Past Due		2,304,607		3,552,709
Residential Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Past Due		35,457		393,410
Consumer Portfolio Segment [Member]
Current		95,435,771		117,773,259
Accruing Past Due 90 Days or More		4,778		14,152
Financing Receivable, Recorded Investment, Nonaccrual Status		267,187		249,091	[1]
Loans and Leases Receivable, Net of Deferred Income, Total	[3]	95,911,569		118,610,799
Consumer Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Past Due		190,027		517,537
Consumer Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Past Due		$ 13,806		$ 56,760

[1] Nonaccrual loans/leases included $2,282,495 of TDRs, including $122,598 in C&I loans, $1,336,871 in CRE loans, $700,255 in direct financing leases, $115,190 in residential real estate loans, and $7,581 in installment loans.

[2] 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.

[3] 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.

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