Note 4 - Loans Leases Receivable - Concentration by Industries (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Gross loans/leases receivable	$ 2,964,485,400	$ 2,405,486,985
Lessors of Non-residential Buildings [Member]
Gross loans/leases receivable	$ 400,622,681	$ 359,040,649
Percentage of total loans/leases	14.00%	15.00%
Lessors of Residential Buildings [Member]
Gross loans/leases receivable	$ 370,353,561	$ 166,036,201
Percentage of total loans/leases	12.00%	7.00%
Administration of Urban Planning and Community and Rural Development [Member]
Gross loans/leases receivable	$ 83,343,541	$ 37,097,000
Percentage of total loans/leases	3.00%	2.00%
Bank Holding Companies [Member]
Gross loans/leases receivable	$ 66,950,294	$ 66,069,612
Percentage of total loans/leases	2.00%	3.00%
Nonresidential Property Managers [Member]
Gross loans/leases receivable	$ 51,984,722	$ 76,504,076
Percentage of total loans/leases	2.00%	3.00%