Note 4 - Loans and Allowance for Credit Losses (Details) - Recorded Investment in Loans Evaluated for Impairment (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014		Dec. 31, 2013		Mar. 31, 2013	Dec. 31, 2012
Allowance for credit losses:
Individually evaluated for impairment	$ 1,545		$ 1,496
Collectively evaluated for impairment	33,257		32,890
Total	34,802		34,386		33,047
Carrying value of loans:
Individually evaluated for impairment	19,925		21,042
Collectively evaluated for impairment	1,791,477		1,801,766
Purchased loans with evidence of credit deterioration	4,917		4,936			14,629
Total	1,816,319		1,827,744
Commercial [Member]
Allowance for credit losses:
Individually evaluated for impairment	100		100
Collectively evaluated for impairment	5,815		5,563
Total	5,915		5,663		7,199
Carrying value of loans:
Individually evaluated for impairment	3,675		3,901
Collectively evaluated for impairment	356,476		334,923
Total	360,151		338,824
Commercial Real Estate Loans [Member]
Allowance for credit losses:
Individually evaluated for impairment	550		1,243
Collectively evaluated for impairment	10,709		10,827
Total	11,259		12,070		10,968
Carrying value of loans:
Individually evaluated for impairment	2,761		3,357
Collectively evaluated for impairment	592,449		593,296
Total	595,210		596,653
Construction [Member]
Allowance for credit losses:
Collectively evaluated for impairment	630		639
Total	630		639		480
Carrying value of loans:
Collectively evaluated for impairment	9,837		10,723
Total	9,837		10,723
Residential Real Estate Loans [Member]
Allowance for credit losses:
Collectively evaluated for impairment	491		405
Total	491		405		539
Carrying value of loans:
Collectively evaluated for impairment	170,176		176,196
Total	170,176		176,196
Consumer Installment And Other [Member]
Allowance for credit losses:
Collectively evaluated for impairment	3,253		3,695
Total	3,253		3,695		3,221
Carrying value of loans:
Collectively evaluated for impairment	394,128		400,888
Total	394,128		400,888
Purchased Non-Covered Loans [Member]
Allowance for credit losses:
Individually evaluated for impairment	895
Collectively evaluated for impairment	1,930
Total	2,825
Carrying value of loans:
Individually evaluated for impairment	13,489		3,785
Collectively evaluated for impairment	249,684		47,571
Purchased loans with evidence of credit deterioration	4,675		2,434
Total	267,848		53,790
Purchased Covered Loans [Member]
Allowance for credit losses:
Individually evaluated for impairment			153
Collectively evaluated for impairment			1,408
Total			1,561		738
Carrying value of loans:
Individually evaluated for impairment			9,999
Collectively evaluated for impairment	18,727		238,169
Purchased loans with evidence of credit deterioration	242		2,502
Total	18,969	[1]	250,670	[1]
Unallocated Financing Receivable [Member]
Allowance for credit losses:
Collectively evaluated for impairment	10,429		10,353
Total	$ 10,429		$ 10,353		$ 9,902

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