Note 5 - Loans and Allowance for Credit Losses (Detail) - Allowance for Credit Losses (USD $) In Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2011	Sep. 30, 2011
Allowance for credit losses:
Balance at beginning of period	$ 33,008	$ 35,636
Additions:
Provision	2,800	8,400
Deductions:
Chargeoffs	(3,652)	(14,116)
Recoveries	737	2,973
Net loan and lease chargeoffs	(2,915)	(11,143)
Balance at end of period	32,893	32,893
Liability for off-balance sheet credit exposure	2,693	2,693
Total allowance for credit losses	35,586	35,586
Commercial [Member]
Allowance for credit losses:
Balance at beginning of period	6,729	8,094
Additions:
Provision	539	3,518
Deductions:
Chargeoffs	(799)	(5,786)
Recoveries	190	833
Net loan and lease chargeoffs	(609)	(4,953)
Balance at end of period	6,659	6,659
Liability for off-balance sheet credit exposure	1,835	1,835
Total allowance for credit losses	8,494	8,494
Commercial Real Estate Loans [Member]
Allowance for credit losses:
Balance at beginning of period	10,241	9,607
Additions:
Provision	1,422	2,057
Deductions:
Chargeoffs	(398)	(399)
Net loan and lease chargeoffs	(398)	(399)
Balance at end of period	11,265	11,265
Liability for off-balance sheet credit exposure	1	1
Total allowance for credit losses	11,266	11,266
Construction [Member]
Allowance for credit losses:
Balance at beginning of period	3,959	3,260
Additions:
Provision	(826)	1,347
Deductions:
Chargeoffs	(452)	(1,926)
Net loan and lease chargeoffs	(452)	(1,926)
Balance at end of period	2,681	2,681
Liability for off-balance sheet credit exposure	62	62
Total allowance for credit losses	2,743	2,743
Residential Real Estate Loans [Member]
Allowance for credit losses:
Balance at beginning of period	466	617
Additions:
Provision	317	693
Deductions:
Chargeoffs		(527)
Net loan and lease chargeoffs		(527)
Balance at end of period	783	783
Total allowance for credit losses	783	783
Consumer Installment And Other [Member]
Allowance for credit losses:
Balance at beginning of period	3,522	6,372
Additions:
Provision	539	(429)
Deductions:
Chargeoffs	(1,575)	(5,050)
Recoveries	547	2,140
Net loan and lease chargeoffs	(1,028)	(2,910)
Balance at end of period	3,033	3,033
Liability for off-balance sheet credit exposure	150	150
Total allowance for credit losses	3,183	3,183
Unallocated [Member]
Allowance for credit losses:
Balance at beginning of period	8,091	7,686
Additions:
Provision	381	786
Deductions:
Balance at end of period	8,472	8,472
Liability for off-balance sheet credit exposure	645	645
Total allowance for credit losses	9,117	9,117
Purchased Covered Loans [Member]
Additions:
Provision	428	428
Deductions:
Chargeoffs	(428)	(428)
Net loan and lease chargeoffs	$ (428)	$ (428)