Note 3 - Loans/Leases Receivable (Detail) - Allowance for Estimated Losses on Loans/Leases (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Loans/leases receivable	$ 1,224,875,461		$ 1,224,875,461		$ 1,181,956,235
Provisions charged to expense	1,496,194	2,456,965	3,325,109	5,196,850
Before Deferred Loan Costs/Fees [Member] | Commercial and Industrial [Member]
Balance, beginning	4,180,792	7,124,444	4,878,006	7,548,922
Balance, ending	4,173,481	5,621,389	4,173,481	5,621,389
Loans/leases individually evaluated for impairment	1,071,050		1,071,050		2,152,855
Loans/leases collectively evaluated for impairment	353,932,838		353,932,838		348,641,423
Loans/leases receivable	355,003,888		355,003,888		350,794,278
Allowance as a percentage of loans/leases individually evaluated for impairment	25.64%		25.64%		41.95%
Allowance as a percentage of loans/leases collectively evaluated for impairment	1.10%		1.10%		1.14%
Allowance as a percentage of loans/leases	1.18%		1.18%		1.39%
Allowance for loans/leases individually evaluated for impairment	274,666		274,666		903,187
Allowance for loans/leases collectively evaluated for impairment	3,898,815		3,898,815		3,974,819
Provisions charged to expense	136,766	(211,491)	(637,852)	1,005,002
Loans/leases charged off	(214,036)	(1,465,577)	(669,778)	(3,256,194)
Recoveries on loans/leases previously charged off	69,959	174,013	603,105	323,659
Before Deferred Loan Costs/Fees [Member] | Other commercial real estate [Member]
Balance, beginning	10,709,991	8,602,639	10,596,958	9,087,315
Balance, ending	11,053,857	10,608,605	11,053,857	10,608,605
Loans/leases individually evaluated for impairment	18,450,756		18,450,756		24,281,365
Loans/leases collectively evaluated for impairment	576,452,994		576,452,994		553,522,485
Loans/leases receivable	594,903,750		594,903,750		577,803,850
Allowance as a percentage of loans/leases individually evaluated for impairment	18.87%		18.87%		17.70%
Allowance as a percentage of loans/leases collectively evaluated for impairment	1.31%		1.31%		1.14%
Allowance as a percentage of loans/leases	1.86%		1.86%		1.83%
Allowance for loans/leases individually evaluated for impairment	3,482,125		3,482,125		4,297,738
Allowance for loans/leases collectively evaluated for impairment	7,571,732		7,571,732		6,299,220
Provisions charged to expense	721,358	2,645,457	2,254,732	3,038,359
Loans/leases charged off	(552,959)	(852,174)	(1,980,946)	(1,773,711)
Recoveries on loans/leases previously charged off	175,467	212,683	183,113	256,642
Before Deferred Loan Costs/Fees [Member] | Leases receivable [Member]
Balance, beginning	1,610,999	1,591,309	1,339,496	1,530,572
Balance, ending	1,884,985	1,051,960	1,884,985	1,051,960
Loans/leases individually evaluated for impairment	1,094,724		1,094,724		1,306,663
Loans/leases collectively evaluated for impairment	100,944,144		100,944,144		91,905,699
Loans/leases receivable	102,038,868		102,038,868		93,212,362
Allowance as a percentage of loans/leases individually evaluated for impairment	14.42%		14.42%		5.10%
Allowance as a percentage of loans/leases collectively evaluated for impairment	1.71%		1.71%		1.38%
Allowance as a percentage of loans/leases	1.85%		1.85%		1.44%
Allowance for loans/leases individually evaluated for impairment	157,900		157,900		66,675
Allowance for loans/leases collectively evaluated for impairment	1,727,085		1,727,085		1,272,821
Provisions charged to expense	350,194	159,965	924,109	463,850
Loans/leases charged off	(111,326)	(701,658)	(454,590)	(945,104)
Recoveries on loans/leases previously charged off	35,118	2,344	75,970	2,642
Before Deferred Loan Costs/Fees [Member] | Residential Real Estate [Member]
Balance, beginning	986,714	757,075	704,946	748,028
Balance, ending	1,036,909	849,107	1,036,909	849,107
Loans/leases individually evaluated for impairment	1,517,304		1,517,304		1,133,474
Loans/leases collectively evaluated for impairment	110,974,915		110,974,915		96,973,577
Loans/leases receivable	112,492,219		112,492,219		98,107,051
Allowance as a percentage of loans/leases individually evaluated for impairment	11.15%		11.15%		4.93%
Allowance as a percentage of loans/leases collectively evaluated for impairment	0.78%		0.78%		0.67%
Allowance as a percentage of loans/leases	0.92%		0.92%		0.72%
Allowance for loans/leases individually evaluated for impairment	169,196		169,196		55,884
Allowance for loans/leases collectively evaluated for impairment	867,713		867,713		649,062
Provisions charged to expense	233,226	92,032	519,751	101,079
Loans/leases charged off	(183,031)		(187,788)
Before Deferred Loan Costs/Fees [Member] | Installment and Other Consumer [Member]
Balance, beginning	1,236,039	1,727,165	1,269,856	1,449,819
Balance, ending	1,267,516	1,447,425	1,267,516	1,447,425
Loans/leases individually evaluated for impairment	759,478		759,478		984,806
Loans/leases collectively evaluated for impairment	76,078,511		76,078,511		77,238,274
Loans/leases receivable	76,837,989		76,837,989		78,223,080
Allowance as a percentage of loans/leases individually evaluated for impairment	9.04%		9.04%		2.32%
Allowance as a percentage of loans/leases collectively evaluated for impairment	1.58%		1.58%		1.61%
Allowance as a percentage of loans/leases	1.65%		1.65%		1.62%
Allowance for loans/leases individually evaluated for impairment	68,673		68,673		22,819
Allowance for loans/leases collectively evaluated for impairment	1,198,843		1,198,843		1,247,037
Provisions charged to expense	54,650	(228,998)	264,369	588,560
Loans/leases charged off	(88,378)	(84,358)	(416,179)	(701,390)
Recoveries on loans/leases previously charged off	65,205	33,616	149,470	110,436
Before Deferred Loan Costs/Fees [Member]
Balance, beginning	18,724,535	19,802,632	18,789,262	20,364,656
Balance, ending	19,416,748	19,578,486	19,416,748	19,578,486
Loans/leases individually evaluated for impairment	22,893,312		22,893,312		29,859,163
Loans/leases collectively evaluated for impairment	1,218,383,402		1,218,383,402		1,168,281,458
Loans/leases receivable	1,241,276,714		1,241,276,714		1,198,140,621
Allowance as a percentage of loans/leases individually evaluated for impairment	18.14%		18.14%		17.91%
Allowance as a percentage of loans/leases collectively evaluated for impairment	1.25%		1.25%		1.15%
Allowance as a percentage of loans/leases	1.56%		1.56%		1.56%
Allowance for loans/leases individually evaluated for impairment	4,152,560		4,152,560		5,346,303
Allowance for loans/leases collectively evaluated for impairment	15,264,188		15,264,188		13,442,959
Provisions charged to expense	1,496,194	2,456,965	3,325,109	5,196,850
Loans/leases charged off	(1,149,730)	(3,103,767)	(3,709,281)	(6,676,399)
Recoveries on loans/leases previously charged off	345,749	422,656	1,011,658	693,379
Leases receivable [Member]
Balance, beginning					1,339,496
Balance, ending	$ 1,884,985		$ 1,884,985		$ 1,339,496