Note 3 - Loans/Leases Receivable (Detail) - Recorded Investment by Credit Quality Indicators, Commercial Real Estate (USD $)	Sep. 30, 2012	Dec. 31, 2011
Internally assigned risk rating	$ 1,224,875,461	$ 1,181,956,235
Commercial and Industrial [Member] | Pass [Member]
Internally assigned risk rating	331,637,518	324,225,905
Commercial and Industrial [Member] | Special Mention [Member]
Internally assigned risk rating	7,920,533	8,814,497
Commercial and Industrial [Member] | Substandard [Member]
Internally assigned risk rating	15,445,837	17,753,876
Commercial and Industrial [Member] | Doubtful [Member]
Internally assigned risk rating	0	0
Commercial and Industrial [Member] | Total [Member]
Internally assigned risk rating	355,003,888	350,794,278
Owner-occupied commercial real estate [Member] | Pass [Member]
Internally assigned risk rating	193,587,897	158,955,618
Owner-occupied commercial real estate [Member] | Special Mention [Member]
Internally assigned risk rating	4,213,076	2,700,496
Owner-occupied commercial real estate [Member] | Substandard [Member]
Internally assigned risk rating	1,987,151	6,134,507
Owner-occupied commercial real estate [Member] | Doubtful [Member]
Internally assigned risk rating	0	0
Owner-occupied commercial real estate [Member] | Total [Member]
Internally assigned risk rating	199,788,124	167,790,621
Commercial construction, land development, and other land [Member] | Pass [Member]
Internally assigned risk rating	42,177,159	46,268,554
Commercial construction, land development, and other land [Member] | Special Mention [Member]
Internally assigned risk rating	560,086	764,586
Commercial construction, land development, and other land [Member] | Substandard [Member]
Internally assigned risk rating	6,454,664	13,351,598
Commercial construction, land development, and other land [Member] | Doubtful [Member]
Internally assigned risk rating	0	0
Commercial construction, land development, and other land [Member] | Total [Member]
Internally assigned risk rating	49,191,909	60,384,738
Non-owner occupied Commercial Real Estate [Member] | Pass [Member]
Internally assigned risk rating	311,918,867	310,401,972
Non-owner occupied Commercial Real Estate [Member] | Special Mention [Member]
Internally assigned risk rating	8,660,810	13,754,798
Non-owner occupied Commercial Real Estate [Member] | Substandard [Member]
Internally assigned risk rating	25,344,040	25,471,721
Non-owner occupied Commercial Real Estate [Member] | Doubtful [Member]
Internally assigned risk rating	0	0
Non-owner occupied Commercial Real Estate [Member] | Total [Member]
Internally assigned risk rating	345,923,717	349,628,491
Total [Member] | Pass [Member]
Internally assigned risk rating	879,321,441	839,852,049
Total [Member] | Special Mention [Member]
Internally assigned risk rating	21,354,505	26,034,377
Total [Member] | Substandard [Member]
Internally assigned risk rating	49,231,692	62,711,702
Total [Member] | Doubtful [Member]
Internally assigned risk rating	0	0
Total [Member] | Total [Member]
Internally assigned risk rating	$ 949,907,638	$ 928,598,128