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Note 4 - Loans Leases Receivable - Composition of the Loan Lease Portfolio (Details) - USD ($)	Sep. 30, 2018	Jun. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Dec. 31, 2016
Gross loans/leases receivable	$ 3,653,386,367		$ 2,964,485,400
Less allowance	(43,077,457)	$ (37,545,076)	(34,355,728)	$ (34,982,341)	$ (33,356,632)	$ (30,757,448)
Net loans/leases receivable	3,610,308,910		2,930,129,672
Plus deferred loan/lease origination costs, net of fees	9,286,864		7,771,907
Loans and Leases Receivable, Net of Deferred Income	3,644,099,503		2,956,713,493
Commercial Portfolio Segment [Member]
Less allowance	(18,916,859)	(15,233,871)	(14,323,036)	(14,402,715)	(14,207,733)	(12,545,110)
Loans and Leases Receivable, Net of Deferred Income	1,380,542,524		1,134,516,315
Commercial Real Estate Portfolio Segment [Member]
Less allowance	(17,716,198)	(15,819,040)	(13,962,688)	(14,359,374)	(12,999,233)	(11,670,609)
Loans and Leases Receivable, Net of Deferred Income	1,727,326,190		1,303,491,882
Commercial Real Estate Portfolio Segment [Member] \| Owner Occupied Commercial Real Estate Loans [Member]
Loans and Leases Receivable, Net of Deferred Income	449,056,125		332,742,477
Commercial Real Estate Portfolio Segment [Member] \| Construction Loans [Member]
Loans and Leases Receivable, Net of Deferred Income	224,295,259		186,402,404
Commercial Real Estate Portfolio Segment [Member] \| Other Non-owner Occupied Commercial Real Estate Loans [Member]
Loans and Leases Receivable, Net of Deferred Income	1,053,974,806		784,347,000
Finance Leases Portfolio Segment [Member]
Net minimum lease payments to be received	140,055,010		156,583,887
Estimated unguaranteed residual values of leased assets	929,932		929,932
Unearned lease/residual income	(14,233,159)		(16,065,587)
Gross loans/leases receivable	130,791,418		146,072,259
Less allowance	(2,632,247)	(2,724,355)	(2,382,098)	(2,652,758)	(2,638,301)	(3,111,898)
Net loans/leases receivable	128,159,171		143,690,161
Plus deferred loan/lease origination costs, net of fees	4,039,635		4,624,027
Loans and Leases Receivable, Net of Deferred Income	126,751,783		141,448,232
Residential Portfolio Segment [Member]
Less allowance	(2,506,838)	(2,433,102)	(2,466,431)	(2,398,978)	(2,430,454)	(2,342,344)
Loans and Leases Receivable, Net of Deferred Income	309,287,535		258,646,265
Consumer Portfolio Segment [Member]
Less allowance	(1,305,315)	$ (1,334,708)	(1,221,475)	$ (1,168,516)	$ (1,080,911)	$ (1,087,487)
Loans and Leases Receivable, Net of Deferred Income	$ 100,191,471		$ 118,610,799