Note 4 - Loans and Allowance for Credit Losses (Details) - Recorded Investment in Loans Evaluated for Impairment (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014		Dec. 31, 2013		Sep. 30, 2013	Dec. 31, 2012
Allowance for credit losses:
Individually evaluated for impairment	$ 892		$ 1,496
Collectively evaluated for impairment	33,570		32,890
Total	34,462		34,386		34,609
Carrying value of loans:
Individually evaluated for impairment	18,869		21,042
Collectively evaluated for impairment	1,708,869		1,801,766
Purchased loans with evidence of credit deterioration	4,644		4,936			14,629
Total	1,732,382		1,827,744
Commercial [Member]
Allowance for credit losses:
Individually evaluated for impairment			100
Collectively evaluated for impairment	6,058		5,563
Total	6,058		5,663		5,788
Carrying value of loans:
Individually evaluated for impairment	2,714		3,901
Collectively evaluated for impairment	367,346		334,923
Total	370,060		338,824
Commercial Real Estate Loans [Member]
Allowance for credit losses:
Individually evaluated for impairment			1,243
Collectively evaluated for impairment	10,063		10,827
Total	10,063		12,070		11,635
Carrying value of loans:
Individually evaluated for impairment	3,037		3,357
Collectively evaluated for impairment	570,142		593,296
Total	573,179		596,653
Construction [Member]
Allowance for credit losses:
Collectively evaluated for impairment	547		639
Total	547		639		634
Carrying value of loans:
Collectively evaluated for impairment	9,824		10,723
Total	9,824		10,723
Residential Real Estate Loans [Member]
Allowance for credit losses:
Collectively evaluated for impairment	392		405
Total	392		405		428
Carrying value of loans:
Collectively evaluated for impairment	156,794		176,196
Total	156,794		176,196
Consumer Installment And Other [Member]
Allowance for credit losses:
Collectively evaluated for impairment	2,689		3,695
Total	2,689		3,695		3,847
Carrying value of loans:
Collectively evaluated for impairment	379,708		400,888
Total	379,708		400,888
Purchased Non-Covered Loans [Member]
Allowance for credit losses:
Individually evaluated for impairment	892
Collectively evaluated for impairment	1,813
Total	2,705
Carrying value of loans:
Individually evaluated for impairment	13,118		3,785
Collectively evaluated for impairment	207,764		47,571
Purchased loans with evidence of credit deterioration	4,412		2,434
Total	225,294		53,790
Purchased Covered Loans [Member]
Allowance for credit losses:
Individually evaluated for impairment			153
Collectively evaluated for impairment			1,408
Total			1,561		1,566
Carrying value of loans:
Individually evaluated for impairment			9,999
Collectively evaluated for impairment	17,291		238,169
Purchased loans with evidence of credit deterioration	232		2,502
Total	17,523	[1]	250,670	[1]
Unallocated Financing Receivable [Member]
Allowance for credit losses:
Collectively evaluated for impairment	12,008		10,353
Total	$ 12,008		$ 10,353		$ 10,711

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