Note 4 - Loans and Allowance for Loan Losses (Details) - Age Analysis of Past Due Loans (USD $)	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014
Commercial:
Loans	$ 2,120,760,000	$ 2,089,277,000
Commercial and Industrial [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Originated Loan [Member]
Commercial:
Loans- 30 to 59 days past due	0	0
Commercial and Industrial [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Acquired Loan [Member]
Commercial:
Loans- 30 to 59 days past due	285,000	29,000
Commercial and Industrial [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Originated Loan [Member]
Commercial:
Loans- 30 to 59 days past due	0	0
Commercial and Industrial [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Acquired Loan [Member]
Commercial:
Loans- 30 to 59 days past due	0	32,000
Commercial and Industrial [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Originated Loan [Member]
Commercial:
Loans- 30 to 59 days past due	0	0
Commercial and Industrial [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Acquired Loan [Member]
Commercial:
Loans- 30 to 59 days past due	711,000	76,000
Commercial and Industrial [Member] | Originated Loan [Member]
Commercial:
Loans- 30 to 59 days past due	0	0
Loans- Current	434,211,000	384,570,000
Loans	434,211,000	384,570,000
Loans- Recorded Balance >89days and accruing	0	0
Commercial and Industrial [Member] | Acquired Loan [Member]
Commercial:
Loans- 30 to 59 days past due	996,000	137,000
Loans- Current	152,468,000	165,900,000
Loans	153,464,000	166,037,000
Loans- Recorded Balance >89days and accruing	0	0
Commercial and Industrial [Member]
Commercial:
Loans	587,675,000	550,607,000
Vacant Land and Land Development and Residential Construction Loan [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Originated Loan [Member]
Commercial:
Loans- 30 to 59 days past due	0	0
Vacant Land and Land Development and Residential Construction Loan [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Acquired Loan [Member]
Commercial:
Loans- 30 to 59 days past due	26,000	0
Vacant Land and Land Development and Residential Construction Loan [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Originated Loan [Member]
Commercial:
Loans- 30 to 59 days past due	0	0
Vacant Land and Land Development and Residential Construction Loan [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Acquired Loan [Member]
Commercial:
Loans- 30 to 59 days past due	0	38,000
Vacant Land and Land Development and Residential Construction Loan [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Originated Loan [Member]
Commercial:
Loans- 30 to 59 days past due	0	0
Vacant Land and Land Development and Residential Construction Loan [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Acquired Loan [Member]
Commercial:
Loans- 30 to 59 days past due	0	0
Vacant Land and Land Development and Residential Construction Loan [Member] | Originated Loan [Member]
Commercial:
Loans- 30 to 59 days past due	0	0
Loans- Current	35,948,000	29,826,000
Loans	35,948,000	29,826,000
Loans- Recorded Balance >89days and accruing	0	0
Vacant Land and Land Development and Residential Construction Loan [Member] | Acquired Loan [Member]
Commercial:
Loans- 30 to 59 days past due	26,000	38,000
Loans- Current	20,076,000	22,110,000
Loans	20,102,000	22,148,000
Loans- Recorded Balance >89days and accruing	0	0
Vacant Land and Land Development and Residential Construction Loan [Member]
Commercial:
Loans	56,050,000	51,974,000
Real Estate Owner Occupied Loan [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Originated Loan [Member]
Commercial:
Loans- 30 to 59 days past due	0	0
Real Estate Owner Occupied Loan [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Acquired Loan [Member]
Commercial:
Loans- 30 to 59 days past due	1,371,000	51,000
Real Estate Owner Occupied Loan [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Originated Loan [Member]
Commercial:
Loans- 30 to 59 days past due	0	0
Real Estate Owner Occupied Loan [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Acquired Loan [Member]
Commercial:
Loans- 30 to 59 days past due	0	425,000
Real Estate Owner Occupied Loan [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Originated Loan [Member]
Commercial:
Loans- 30 to 59 days past due	106,000	120,000
Real Estate Owner Occupied Loan [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Acquired Loan [Member]
Commercial:
Loans- 30 to 59 days past due	1,041,000	1,625,000
Real Estate Owner Occupied Loan [Member] | Originated Loan [Member]
Commercial:
Loans- 30 to 59 days past due	106,000	120,000
Loans- Current	302,273,000	291,638,000
Loans	302,379,000	291,758,000
Loans- Recorded Balance >89days and accruing	0	0
Real Estate Owner Occupied Loan [Member] | Acquired Loan [Member]
Commercial:
Loans- 30 to 59 days past due	2,412,000	2,101,000
Loans- Current	127,204,000	136,529,000
Loans	129,616,000	138,630,000
Loans- Recorded Balance >89days and accruing	0	0
Real Estate Owner Occupied Loan [Member]
Commercial:
Loans	431,995,000	430,388,000
Real Estate Non Owner Occupied Loan [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Originated Loan [Member]
Commercial:
Loans- 30 to 59 days past due	0	0
Real Estate Non Owner Occupied Loan [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Acquired Loan [Member]
Commercial:
Loans- 30 to 59 days past due	0	68,000
Real Estate Non Owner Occupied Loan [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Originated Loan [Member]
Commercial:
Loans- 30 to 59 days past due	0	0
Real Estate Non Owner Occupied Loan [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Acquired Loan [Member]
Commercial:
Loans- 30 to 59 days past due	0	598,000
Real Estate Non Owner Occupied Loan [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Originated Loan [Member]
Commercial:
Loans- 30 to 59 days past due	113,000	116,000
Real Estate Non Owner Occupied Loan [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Acquired Loan [Member]
Commercial:
Loans- 30 to 59 days past due	296,000	395,000
Real Estate Non Owner Occupied Loan [Member] | Originated Loan [Member]
Commercial:
Loans- 30 to 59 days past due	113,000	116,000
Loans- Current	423,268,000	410,861,000
Loans	423,381,000	410,977,000
Loans- Recorded Balance >89days and accruing	0	0
Real Estate Non Owner Occupied Loan [Member] | Acquired Loan [Member]
Commercial:
Loans- 30 to 59 days past due	296,000	1,061,000
Loans- Current	142,475,000	147,536,000
Loans	142,771,000	148,597,000
Loans- Recorded Balance >89days and accruing	0	0
Real Estate Non Owner Occupied Loan [Member]
Commercial:
Loans	566,152,000	559,574,000
Real Estate Multi Family and Residential Rental Loan [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Originated Loan [Member]
Commercial:
Loans- 30 to 59 days past due	0	0
Real Estate Multi Family and Residential Rental Loan [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Acquired Loan [Member]
Commercial:
Loans- 30 to 59 days past due	0	37,000
Real Estate Multi Family and Residential Rental Loan [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Originated Loan [Member]
Commercial:
Loans- 30 to 59 days past due	0	0
Real Estate Multi Family and Residential Rental Loan [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Acquired Loan [Member]
Commercial:
Loans- 30 to 59 days past due	69,000	0
Real Estate Multi Family and Residential Rental Loan [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Originated Loan [Member]
Commercial:
Loans- 30 to 59 days past due	0	0
Real Estate Multi Family and Residential Rental Loan [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Acquired Loan [Member]
Commercial:
Loans- 30 to 59 days past due	93,000	105,000
Real Estate Multi Family and Residential Rental Loan [Member] | Originated Loan [Member]
Commercial:
Loans- 30 to 59 days past due	0	0
Loans- Current	34,922,000	36,058,000
Loans	34,922,000	36,058,000
Loans- Recorded Balance >89days and accruing	0	0
Real Estate Multi Family and Residential Rental Loan [Member] | Acquired Loan [Member]
Commercial:
Loans- 30 to 59 days past due	162,000	142,000
Loans- Current	82,393,000	86,560,000
Loans	82,555,000	86,702,000
Loans- Recorded Balance >89days and accruing	0	0
Real Estate Multi Family and Residential Rental Loan [Member]
Commercial:
Loans	117,477,000	122,760,000
Commercial Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Originated Loan [Member]
Commercial:
Loans- 30 to 59 days past due	0	0
Commercial Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Acquired Loan [Member]
Commercial:
Loans- 30 to 59 days past due	1,682,000	185,000
Commercial Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Originated Loan [Member]
Commercial:
Loans- 30 to 59 days past due	0	0
Commercial Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Acquired Loan [Member]
Commercial:
Loans- 30 to 59 days past due	69,000	1,093,000
Commercial Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Originated Loan [Member]
Commercial:
Loans- 30 to 59 days past due	219,000	236,000
Commercial Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Acquired Loan [Member]
Commercial:
Loans- 30 to 59 days past due	2,141,000	2,201,000
Commercial Portfolio Segment [Member] | Originated Loan [Member]
Commercial:
Loans- 30 to 59 days past due	219,000	236,000
Loans- Current	1,230,622,000	1,152,953,000
Loans	1,230,841,000	1,153,189,000
Loans- Recorded Balance >89days and accruing	0	0
Commercial Portfolio Segment [Member] | Acquired Loan [Member]
Commercial:
Loans- 30 to 59 days past due	3,892,000	3,479,000
Loans- Current	524,616,000	558,635,000
Loans	528,508,000	562,114,000
Loans- Recorded Balance >89days and accruing	0	0
Home Equity and Other [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Originated Loan [Member]
Commercial:
Loans- 30 to 59 days past due	133,000	38,000
Home Equity and Other [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Acquired Loan [Member]
Commercial:
Loans- 30 to 59 days past due	245,000	445,000
Home Equity and Other [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Originated Loan [Member]
Commercial:
Loans- 30 to 59 days past due	300,000	3,000
Home Equity and Other [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Acquired Loan [Member]
Commercial:
Loans- 30 to 59 days past due	90,000	419,000
Home Equity and Other [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Originated Loan [Member]
Commercial:
Loans- 30 to 59 days past due	0	0
Home Equity and Other [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Acquired Loan [Member]
Commercial:
Loans- 30 to 59 days past due	362,000	155,000
Home Equity and Other [Member] | Originated Loan [Member]
Commercial:
Loans- 30 to 59 days past due	433,000	41,000
Loans- Current	53,274,000	50,018,000
Loans	53,707,000	50,059,000
Loans- Recorded Balance >89days and accruing	0	0
Home Equity and Other [Member] | Acquired Loan [Member]
Commercial:
Loans- 30 to 59 days past due	697,000	1,019,000
Loans- Current	98,582,000	108,200,000
Loans	99,279,000	109,219,000
Loans- Recorded Balance >89days and accruing	0	26,000
Home Equity and Other [Member]
Commercial:
Loans	152,986,000	159,278,000
1-4 Family Mortgages [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Originated Loan [Member]
Commercial:
Loans- 30 to 59 days past due	0	0
1-4 Family Mortgages [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Acquired Loan [Member]
Commercial:
Loans- 30 to 59 days past due	1,204,000	1,087,000
1-4 Family Mortgages [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Originated Loan [Member]
Commercial:
Loans- 30 to 59 days past due	84,000	0
1-4 Family Mortgages [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Acquired Loan [Member]
Commercial:
Loans- 30 to 59 days past due	54,000	408,000
1-4 Family Mortgages [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Originated Loan [Member]
Commercial:
Loans- 30 to 59 days past due	321,000	366,000
1-4 Family Mortgages [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Acquired Loan [Member]
Commercial:
Loans- 30 to 59 days past due	1,021,000	750,000
1-4 Family Mortgages [Member] | Originated Loan [Member]
Commercial:
Loans- 30 to 59 days past due	405,000	366,000
Loans- Current	43,760,000	42,502,000
Loans	44,165,000	42,868,000
Loans- Recorded Balance >89days and accruing	0	0
1-4 Family Mortgages [Member] | Acquired Loan [Member]
Commercial:
Loans- 30 to 59 days past due	2,279,000	2,245,000
Loans- Current	161,981,000	169,583,000
Loans	164,260,000	171,828,000
Loans- Recorded Balance >89days and accruing	0	0
1-4 Family Mortgages [Member]
Commercial:
Loans	208,425,000	214,696,000
Retail Loan [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Originated Loan [Member]
Commercial:
Loans- 30 to 59 days past due	133,000	38,000
Retail Loan [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Acquired Loan [Member]
Commercial:
Loans- 30 to 59 days past due	1,449,000	1,532,000
Retail Loan [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Originated Loan [Member]
Commercial:
Loans- 30 to 59 days past due	384,000	3,000
Retail Loan [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Acquired Loan [Member]
Commercial:
Loans- 30 to 59 days past due	144,000	827,000
Retail Loan [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Originated Loan [Member]
Commercial:
Loans- 30 to 59 days past due	321,000	366,000
Retail Loan [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Acquired Loan [Member]
Commercial:
Loans- 30 to 59 days past due	1,383,000	905,000
Retail Loan [Member] | Originated Loan [Member]
Commercial:
Loans- 30 to 59 days past due	838,000	407,000
Loans- Current	97,034,000	92,520,000
Loans	97,872,000	92,927,000
Loans- Recorded Balance >89days and accruing	0	0
Retail Loan [Member] | Acquired Loan [Member]
Commercial:
Loans- 30 to 59 days past due	2,976,000	3,264,000
Loans- Current	260,563,000	277,783,000
Loans	263,539,000	281,047,000
Loans- Recorded Balance >89days and accruing	0	26,000
Retail Loan [Member]
Commercial:
Loans	361,411,000	373,974,000
Financing Receivables, 30 to 59 Days Past Due [Member] | Originated Loan [Member]
Commercial:
Loans- 30 to 59 days past due	133,000	38,000
Financing Receivables, 30 to 59 Days Past Due [Member] | Acquired Loan [Member]
Commercial:
Loans- 30 to 59 days past due	3,131,000	1,717,000
Financing Receivables, 60 to 89 Days Past Due [Member] | Originated Loan [Member]
Commercial:
Loans- 30 to 59 days past due	384,000	3,000
Financing Receivables, 60 to 89 Days Past Due [Member] | Acquired Loan [Member]
Commercial:
Loans- 30 to 59 days past due	213,000	1,920,000
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Originated Loan [Member]
Commercial:
Loans- 30 to 59 days past due	540,000	602,000
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Acquired Loan [Member]
Commercial:
Loans- 30 to 59 days past due	3,524,000	3,106,000
Originated Loan [Member]
Commercial:
Loans- 30 to 59 days past due	1,057,000	643,000
Loans- Current	1,327,656,000	1,245,473,000
Loans	1,328,713,000	1,246,116,000	1,066,796,000
Loans- Recorded Balance >89days and accruing	0	0
Acquired Loan [Member]
Commercial:
Loans- 30 to 59 days past due	6,868,000	6,743,000
Loans- Current	785,179,000	836,418,000
Loans	792,047,000	843,161,000
Loans- Recorded Balance >89days and accruing	$ 0	$ 26,000