Note 3 - Loans/Leases Receivable (Detail) - Aging of the Loan/Lease Portfolio (USD $)	Jun. 30, 2012	Dec. 31, 2011
Current	$ 1,182,808,759	$ 1,168,978,194
30-59 Days Past Due	4,589,208	3,798,637
60-89 Days Past Due	5,705,989	5,257,872
Accruing Past Due 90 Days or More	1,151,891	1,111,079
Nonacrrual Loans/Loans	16,246,760	18,994,839
Total	1,210,502,607	1,198,140,621
Current as a percentage of total loan/lease portfolio	97.71%	97.57%
30-59 Days Past Due as a percentage of total loan/lease portfolio	0.38%	0.32%
60-89 Days Past Due as a percentage of total loan/lease portfolio	0.47%	0.44%
Accruing Past Due 90 Days or More as a percentage of total loan/lease portfolio	0.10%	0.09%
Nonacrrual Loans/Loans as a percentage of total loan/lease portfolio	1.34%	1.59%
Total as a percentage of total loan/lease portfolio	100.00%	100.00%
Commercial and Industrial [Member]
Current	347,348,642	347,417,683
30-59 Days Past Due	834,831	226,394
60-89 Days Past Due	17,821	239,991
Accruing Past Due 90 Days or More	965,673	120,000
Nonacrrual Loans/Loans	1,613,450	2,790,210
Total	350,780,417	350,794,278
Owner-occupied commercial real estate [Member]
Current	187,712,914	166,632,318
30-59 Days Past Due	548,615	146,847
60-89 Days Past Due	0	0
Accruing Past Due 90 Days or More	0	0
Nonacrrual Loans/Loans	687,218	1,011,456
Total	188,948,747	167,790,621
Commercial construction, land development, and other land [Member]
Current	42,799,962	55,741,827
30-59 Days Past Due	0	211,878
60-89 Days Past Due	1,076,387	486,802
Accruing Past Due 90 Days or More	0	968,919
Nonacrrual Loans/Loans	2,787,384	2,975,312
Total	46,663,733	60,384,738
Other commercial real estate [Member]
Current	326,648,116	336,080,128
30-59 Days Past Due	2,178,037	522,323
60-89 Days Past Due	3,258,985	3,732,935
Accruing Past Due 90 Days or More	137,611	0
Nonacrrual Loans/Loans	8,452,069	9,293,105
Total	340,674,818	349,628,491
Leases receivable [Member]
Current	96,813,835	91,273,406
30-59 Days Past Due	796,205	826,187
60-89 Days Past Due	270,034	396,344
Accruing Past Due 90 Days or More	0	0
Nonacrrual Loans/Loans	687,508	716,425
Total	98,567,582	93,212,362
Residential Real Estate [Member]
Current	106,016,069	95,456,433
30-59 Days Past Due	0	1,127,465
60-89 Days Past Due	411,031	389,678
Accruing Past Due 90 Days or More	0	0
Nonacrrual Loans/Loans	1,023,397	1,133,475
Total	107,450,497	98,107,051
Installment and Other Consumer [Member]
Current	75,469,221	76,376,399
30-59 Days Past Due	231,520	737,543
60-89 Days Past Due	671,731	12,122
Accruing Past Due 90 Days or More	48,607	22,160
Nonacrrual Loans/Loans	995,734	1,074,856
Total	$ 77,416,813	$ 78,223,080