Note 4 - Loans and Allowance for Credit Losses (Details) - Credit risk profile by internally assigned grade (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013		Dec. 31, 2012
Grade:
Loans by grade	$ 1,939,341		$ 2,111,357
Commercial [Member] | Pass [Member]
Grade:
Loans by grade	297,214		324,452
Commercial [Member] | Substandard [Member]
Grade:
Loans by grade	10,271		11,413
Commercial [Member] | Doubtful [Member]
Grade:
Loans by grade	2,136		4,251
Commercial [Member]
Grade:
Loans by grade	309,621		340,116
Commercial Real Estate Loans [Member] | Pass [Member]
Grade:
Loans by grade	568,854		599,472
Commercial Real Estate Loans [Member] | Substandard [Member]
Grade:
Loans by grade	45,151		33,455
Commercial Real Estate Loans [Member]
Grade:
Loans by grade	614,005		632,927
Construction [Member] | Pass [Member]
Grade:
Loans by grade	7,557		7,518
Construction [Member] | Substandard [Member]
Grade:
Loans by grade	458		466
Construction [Member]
Grade:
Loans by grade	8,015		7,984
Residential Real Estate Loans [Member] | Pass [Member]
Grade:
Loans by grade	192,790		219,655
Residential Real Estate Loans [Member] | Substandard [Member]
Grade:
Loans by grade	2,532		2,803
Residential Real Estate Loans [Member]
Grade:
Loans by grade	195,322		222,458
Consumer Installment And Other [Member] | Pass [Member]
Grade:
Loans by grade	424,989		459,076
Consumer Installment And Other [Member] | Substandard [Member]
Grade:
Loans by grade	1,137		1,158
Consumer Installment And Other [Member] | Doubtful [Member]
Grade:
Loans by grade	8		46
Consumer Installment And Other [Member] | Unlikely to be Collected Financing Receivable [Member]
Grade:
Loans by grade	206		418
Consumer Installment And Other [Member]
Grade:
Loans by grade	426,340		460,698
Purchased Non-Covered Loans [Member] | Pass [Member]
Grade:
Loans by grade	44,635		51,901
Purchased Non-Covered Loans [Member] | Substandard [Member]
Grade:
Loans by grade	19,049		27,066
Purchased Non-Covered Loans [Member] | Doubtful [Member]
Grade:
Loans by grade	987		1,145
Purchased Non-Covered Loans [Member] | Unlikely to be Collected Financing Receivable [Member]
Grade:
Loans by grade			5
Purchased Non-Covered Loans [Member] | Default Risk Purchase Discount [Member]
Grade:
Loans by grade	(3,609)		(5,226)
Purchased Non-Covered Loans [Member]
Grade:
Loans by grade	61,062		74,891
Purchased Covered Loans [Member] | Pass [Member]
Grade:
Loans by grade	227,835	[1]	274,976	[1]
Purchased Covered Loans [Member] | Substandard [Member]
Grade:
Loans by grade	115,255	[1]	122,815	[1]
Purchased Covered Loans [Member] | Doubtful [Member]
Grade:
Loans by grade	350	[1]	470	[1]
Purchased Covered Loans [Member] | Unlikely to be Collected Financing Receivable [Member]
Grade:
Loans by grade	50	[1]	150	[1]
Purchased Covered Loans [Member] | Default Risk Purchase Discount [Member]
Grade:
Loans by grade	(18,514)	[1]	(26,128)	[1]
Purchased Covered Loans [Member]
Grade:
Loans by grade	324,976	[1]	372,283	[1]
Pass [Member]
Grade:
Loans by grade	1,763,874		1,937,050
Substandard [Member]
Grade:
Loans by grade	193,853		199,176
Doubtful [Member]
Grade:
Loans by grade	3,481		5,912
Unlikely to be Collected Financing Receivable [Member]
Grade:
Loans by grade	256		573
Default Risk Purchase Discount [Member]
Grade:
Loans by grade	$ (22,123)		$ (31,354)

[1] Credit risk profile reflects internally assigned grade of purchased covered loans without regard to FDIC indemnification.