Note 7 - Loans (Detail) - Schedule of Portfolio by Risk Rating (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Gross Loans	$ 6,908,544	$ 7,059,212
Loans held for sale	3,709	760
Pass [Member] | Commercial Loans Member
Gross Loans	1,697,108	1,689,842
Pass [Member] | Real Estate Construction Loans [Member]
Gross Loans	110,965	115,538
Pass [Member] | Commercial Mortgage Loans [Member]
Gross Loans	3,245,353	3,275,431
Pass [Member] | Residential Mortgage And Equity Lines Member
Gross Loans	1,173,660	1,149,225
Pass [Member] | Installment And Other Loans Member
Gross Loans	19,405	17,636
Pass [Member] | Total [Member]
Gross Loans	6,246,491	6,247,672
Pass [Member]
Loans held for sale	3,209
Special Mention [Member] | Commercial Loans Member
Gross Loans	66,297	64,290
Special Mention [Member] | Real Estate Construction Loans [Member]
Gross Loans	21,718	23,555
Special Mention [Member] | Commercial Mortgage Loans [Member]
Gross Loans	112,335	69,925
Special Mention [Member] | Residential Mortgage And Equity Lines Member
Gross Loans	403	4,439
Special Mention [Member] | Installment And Other Loans Member
Gross Loans	66	63
Special Mention [Member] | Total [Member]
Gross Loans	200,819	162,272
Special Mention [Member]
Loans held for sale	0
Substandard [Member] | Commercial Loans Member
Gross Loans	74,643	108,858
Substandard [Member] | Real Estate Construction Loans [Member]
Gross Loans	48,280	90,132
Substandard [Member] | Commercial Mortgage Loans [Member]
Gross Loans	304,748	403,541
Substandard [Member] | Residential Mortgage And Equity Lines Member
Gross Loans	19,500	33,160
Substandard [Member] | Installment And Other Loans Member
Gross Loans	0
Substandard [Member] | Total [Member]
Gross Loans	447,171	635,691
Substandard [Member]
Loans held for sale	0	260
Doubtful [Member] | Commercial Loans Member
Gross Loans	6,801	5,285
Doubtful [Member] | Real Estate Construction Loans [Member]
Gross Loans	7,118	8,147
Doubtful [Member] | Commercial Mortgage Loans [Member]
Gross Loans	0
Doubtful [Member] | Residential Mortgage And Equity Lines Member
Gross Loans	144	145
Doubtful [Member] | Installment And Other Loans Member
Gross Loans	0
Doubtful [Member] | Total [Member]
Gross Loans	14,063	13,577
Doubtful [Member]
Loans held for sale	500	500
Total [Member] | Commercial Loans Member
Gross Loans	1,844,849	1,868,275
Total [Member] | Real Estate Construction Loans [Member]
Gross Loans	188,081	237,372
Total [Member] | Commercial Mortgage Loans [Member]
Gross Loans	3,662,436	3,748,897
Total [Member] | Residential Mortgage And Equity Lines Member
Gross Loans	1,193,707	1,186,969
Total [Member] | Installment And Other Loans Member
Gross Loans	19,471	17,699
Total [Member] | Total [Member]
Gross Loans	6,908,544	7,059,212
Total [Member]
Loans held for sale	3,709	760
Commercial Loans Member
Gross Loans	1,844,849	1,868,275
Real Estate Construction Loans [Member]
Gross Loans	188,081	237,372
Commercial Mortgage Loans [Member]
Gross Loans	3,662,436	3,748,897
Residential Mortgage And Equity Lines Member
Gross Loans	1,193,707	1,186,969
Installment And Other Loans Member
Gross Loans	19,471	17,699
Total [Member]
Gross Loans	$ 6,908,544	$ 7,059,212