Note 4 - Loans and Allowance for Credit Losses (Details) - Credit Risk Profile by Internally Assigned Grade (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014		Dec. 31, 2013
Grade:
Loans by grade	$ 1,816,319		$ 1,827,744
Commercial [Member] | Pass [Member]
Grade:
Loans by grade	349,979		329,667
Commercial [Member] | Substandard [Member]
Grade:
Loans by grade	9,157		8,142
Commercial [Member] | Doubtful [Member]
Grade:
Loans by grade	1,015		1,015
Commercial [Member]
Grade:
Loans by grade	360,151		338,824
Commercial Real Estate Loans [Member] | Pass [Member]
Grade:
Loans by grade	550,932		554,991
Commercial Real Estate Loans [Member] | Substandard [Member]
Grade:
Loans by grade	44,278		41,662
Commercial Real Estate Loans [Member]
Grade:
Loans by grade	595,210		596,653
Construction [Member] | Pass [Member]
Grade:
Loans by grade	9,837		10,274
Construction [Member] | Substandard [Member]
Grade:
Loans by grade			449
Construction [Member]
Grade:
Loans by grade	9,837		10,723
Residential Real Estate Loans [Member] | Pass [Member]
Grade:
Loans by grade	168,110		174,113
Residential Real Estate Loans [Member] | Substandard [Member]
Grade:
Loans by grade	2,066		2,083
Residential Real Estate Loans [Member]
Grade:
Loans by grade	170,176		176,196
Consumer Installment And Other [Member] | Pass [Member]
Grade:
Loans by grade	392,931		399,377
Consumer Installment And Other [Member] | Substandard [Member]
Grade:
Loans by grade	983		1,127
Consumer Installment And Other [Member] | Doubtful [Member]
Grade:
Loans by grade	17		19
Consumer Installment And Other [Member] | Unlikely to be Collected Financing Receivable [Member]
Grade:
Loans by grade	197		365
Consumer Installment And Other [Member]
Grade:
Loans by grade	394,128		400,888
Purchased Non-Covered Loans [Member] | Pass [Member]
Grade:
Loans by grade	209,451		41,490
Purchased Non-Covered Loans [Member] | Substandard [Member]
Grade:
Loans by grade	70,109		14,587
Purchased Non-Covered Loans [Member] | Doubtful [Member]
Grade:
Loans by grade	402		958
Purchased Non-Covered Loans [Member] | Unlikely to be Collected Financing Receivable [Member]
Grade:
Loans by grade	26
Purchased Non-Covered Loans [Member] | Default Risk Purchase Discount [Member]
Grade:
Loans by grade	(12,140)		(3,245)
Purchased Non-Covered Loans [Member]
Grade:
Loans by grade	267,848		53,790
Purchased Covered Loans [Member] | Pass [Member]
Grade:
Loans by grade	17,962	[1]	196,882	[1]
Purchased Covered Loans [Member] | Substandard [Member]
Grade:
Loans by grade	1,650	[1]	64,624	[1]
Purchased Covered Loans [Member] | Doubtful [Member]
Grade:
Loans by grade		[1]	97	[1]
Purchased Covered Loans [Member] | Unlikely to be Collected Financing Receivable [Member]
Grade:
Loans by grade		[1]		[1]
Purchased Covered Loans [Member] | Default Risk Purchase Discount [Member]
Grade:
Loans by grade	(643)	[1]	(10,933)	[1]
Purchased Covered Loans [Member]
Grade:
Loans by grade	18,969	[1]	250,670	[1]
Pass [Member]
Grade:
Loans by grade	1,699,202		1,706,794
Substandard [Member]
Grade:
Loans by grade	128,243		132,674
Doubtful [Member]
Grade:
Loans by grade	1,434		2,089
Unlikely to be Collected Financing Receivable [Member]
Grade:
Loans by grade	223		365
Default Risk Purchase Discount [Member]
Grade:
Loans by grade	$ (12,783)		$ (14,178)

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