Note 4 - Loans/Leases Receivable (Details) - Composition of the Loan/Lease Portfolio (USD $)	Jun. 30, 2013		Mar. 31, 2013	Dec. 31, 2012		Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases	$ 1,530,726,102			$ 1,287,387,639
Less allowance for estimated losses on loans/leases	(21,156,379)		(20,769,462)	(19,925,204)		(18,724,535)	(19,006,644)	(18,789,262)
Loans/leases net of allowance for estimated losses	1,509,569,723			1,267,462,435
Commercial and Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases	470,416,356			394,244,252
Less allowance for estimated losses on loans/leases	(4,790,828)		(4,466,264)	(4,531,545)		(4,180,792)	(4,585,467)	(4,878,006)
Owner-occupied commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases	266,927,092			204,911,308
Commercial construction, land development, and other land [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases	48,013,677			44,962,381
Other commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases	409,065,105			344,105,550
Total Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases	724,005,874			593,979,239
Leases receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases	114,754,757			103,685,656
Plus deferred loan/lease origination costs	4,318,828			3,907,140
Total Loans/Leases plus deferred loan/lease origination costs	119,073,585			107,592,796
Less allowance for estimated losses on loans/leases	(2,187,605)		(2,296,523)	(1,990,395)		(1,610,999)	(1,366,528)	(1,339,496)
Loans/leases net of allowance for estimated losses	116,885,980			105,602,401
* Direct financing leases:
Net minimum lease payments to be received	129,915,909			117,719,380
Estimated unguaranteed residual values of leased assets	1,344,853			1,095,848
Unearned lease/residual income	(16,506,005)			(15,129,572)
Mortgage Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases	143,093,342	[1]		115,581,573	[1]
Loans Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases	74,568,755			76,720,514
Total [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases	1,526,839,084			1,284,211,234
Plus deferred loan/lease origination costs	3,887,018			3,176,405
Total Loans/Leases plus deferred loan/lease origination costs	1,530,726,102			1,287,387,639
Less allowance for estimated losses on loans/leases	$ (21,156,379)			$ (19,925,204)

[1] Includes residential real estate loans held for sale totaling $2,083,075 and $4,577,233 as of June 30, 2013, and December 31, 2012, respectively.