Note 4 - Loans and Allowance for Loan Losses (Details) - Age Analysis of Past Due Loans - USD ($)	Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2014
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	$ 2,171,832,000	$ 2,089,277,000
Originated Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	1,651,000	643,000
Loans, current	1,427,972,000	1,245,473,000
Loans	1,429,623,000	1,246,116,000	$ 1,145,097,000
Loans, recorded balance > 89 days and accruing	0	0
Originated Loan [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	64,000	38,000
Originated Loan [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	1,255,000	3,000
Originated Loan [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	332,000	602,000
Acquired Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	6,780,000	6,743,000
Loans, current	735,429,000	836,418,000
Loans	742,209,000	843,161,000
Loans, recorded balance > 89 days and accruing	0	26,000
Acquired Loan [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	1,437,000	1,717,000
Acquired Loan [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	2,663,000	1,920,000
Acquired Loan [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	2,680,000	3,106,000
Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	1,820,431,000	1,715,303,000
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	622,073,000	550,607,000
Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	47,622,000	51,974,000
Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	422,354,000	430,388,000
Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	603,724,000	559,574,000
Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residential Rental Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	124,658,000	122,760,000
Commercial Portfolio Segment [Member] | Originated Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	1,202,000	236,000
Loans, current	1,321,186,000	1,152,953,000
Loans	1,322,388,000	1,153,189,000	1,076,609,000
Loans, recorded balance > 89 days and accruing	0	0
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	0	0
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	1,182,000	0
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	20,000	236,000
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	0	0
Loans, current	487,440,000	384,570,000
Loans	487,440,000	384,570,000
Loans, recorded balance > 89 days and accruing	0	0
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Commercial and Industrial [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	0	0
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Commercial and Industrial [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	0	0
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Commercial and Industrial [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	0	0
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	0	0
Loans, current	28,853,000	29,826,000
Loans	28,853,000	29,826,000
Loans, recorded balance > 89 days and accruing	0	0
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Vacant Land and Land Development and Residential Construction Loan [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	0	0
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Vacant Land and Land Development and Residential Construction Loan [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	0	0
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Vacant Land and Land Development and Residential Construction Loan [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	0	0
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Owner Occupied Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	1,202,000	120,000
Loans, current	296,492,000	291,638,000
Loans	297,694,000	291,758,000
Loans, recorded balance > 89 days and accruing	0	0
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Owner Occupied Loan [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	0	0
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Owner Occupied Loan [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	1,182,000	0
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Owner Occupied Loan [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	20,000	120,000
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Non Owner Occupied Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	0	116,000
Loans, current	469,433,000	410,861,000
Loans	469,433,000	410,977,000
Loans, recorded balance > 89 days and accruing	0	0
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Non Owner Occupied Loan [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	0	0
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Non Owner Occupied Loan [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	0	0
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Non Owner Occupied Loan [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	0	116,000
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Multi Family and Residential Rental Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	0	0
Loans, current	38,968,000	36,058,000
Loans	38,968,000	36,058,000
Loans, recorded balance > 89 days and accruing	0	0
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Multi Family and Residential Rental Loan [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	0	0
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Multi Family and Residential Rental Loan [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	0	0
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Multi Family and Residential Rental Loan [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	0	0
Commercial Portfolio Segment [Member] | Acquired Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	4,792,000	3,479,000
Loans, current	493,251,000	558,635,000
Loans	498,043,000	562,114,000
Loans, recorded balance > 89 days and accruing	0	0
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	310,000	185,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	2,494,000	1,093,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	1,988,000	2,201,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	890,000	137,000
Loans, current	133,743,000	165,900,000
Loans	134,633,000	166,037,000
Loans, recorded balance > 89 days and accruing	0	0
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Commercial and Industrial [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	135,000	29,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Commercial and Industrial [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	0	32,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Commercial and Industrial [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	755,000	76,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	0	38,000
Loans, current	18,769,000	22,110,000
Loans	18,769,000	22,148,000
Loans, recorded balance > 89 days and accruing	0	0
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Vacant Land and Land Development and Residential Construction Loan [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	0	0
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Vacant Land and Land Development and Residential Construction Loan [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	0	38,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Vacant Land and Land Development and Residential Construction Loan [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	0	0
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Owner Occupied Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	919,000	2,101,000
Loans, current	123,741,000	136,529,000
Loans	124,660,000	138,630,000
Loans, recorded balance > 89 days and accruing	0	0
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Owner Occupied Loan [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	76,000	51,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Owner Occupied Loan [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	18,000	425,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Owner Occupied Loan [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	825,000	1,625,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Non Owner Occupied Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	331,000	1,061,000
Loans, current	133,960,000	147,536,000
Loans	134,291,000	148,597,000
Loans, recorded balance > 89 days and accruing	0	0
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Non Owner Occupied Loan [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	85,000	68,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Non Owner Occupied Loan [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	0	598,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Non Owner Occupied Loan [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	246,000	395,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Multi Family and Residential Rental Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	2,652,000	142,000
Loans, current	83,038,000	86,560,000
Loans	85,690,000	86,702,000
Loans, recorded balance > 89 days and accruing	0	0
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Multi Family and Residential Rental Loan [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	14,000	37,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Multi Family and Residential Rental Loan [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	2,476,000	0
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Multi Family and Residential Rental Loan [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	162,000	105,000
Retail Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	351,401,000	373,974,000
Retail Portfolio Segment [Member] | Home Equity and Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	149,494,000	159,278,000
Retail Portfolio Segment [Member] | 1-4 Family Mortgages [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	201,907,000	214,696,000
Retail Portfolio Segment [Member] | Originated Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	449,000	407,000
Loans, current	106,786,000	92,520,000
Loans	107,235,000	92,927,000	$ 68,488,000
Loans, recorded balance > 89 days and accruing	0	0
Retail Portfolio Segment [Member] | Originated Loan [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	64,000	38,000
Retail Portfolio Segment [Member] | Originated Loan [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	73,000	3,000
Retail Portfolio Segment [Member] | Originated Loan [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	312,000	366,000
Retail Portfolio Segment [Member] | Originated Loan [Member] | Home Equity and Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	64,000	41,000
Loans, current	60,353,000	50,018,000
Loans	60,417,000	50,059,000
Loans, recorded balance > 89 days and accruing	0	0
Retail Portfolio Segment [Member] | Originated Loan [Member] | Home Equity and Other [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	64,000	38,000
Retail Portfolio Segment [Member] | Originated Loan [Member] | Home Equity and Other [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	0	3,000
Retail Portfolio Segment [Member] | Originated Loan [Member] | Home Equity and Other [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	0	0
Retail Portfolio Segment [Member] | Originated Loan [Member] | 1-4 Family Mortgages [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	385,000	366,000
Loans, current	46,433,000	42,502,000
Loans	46,818,000	42,868,000
Loans, recorded balance > 89 days and accruing	0	0
Retail Portfolio Segment [Member] | Originated Loan [Member] | 1-4 Family Mortgages [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	0	0
Retail Portfolio Segment [Member] | Originated Loan [Member] | 1-4 Family Mortgages [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	73,000	0
Retail Portfolio Segment [Member] | Originated Loan [Member] | 1-4 Family Mortgages [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	312,000	366,000
Retail Portfolio Segment [Member] | Acquired Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	1,988,000	3,264,000
Loans, current	242,178,000	277,783,000
Loans	244,166,000	281,047,000
Loans, recorded balance > 89 days and accruing	0	26,000
Retail Portfolio Segment [Member] | Acquired Loan [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	1,127,000	1,532,000
Retail Portfolio Segment [Member] | Acquired Loan [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	169,000	827,000
Retail Portfolio Segment [Member] | Acquired Loan [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	692,000	905,000
Retail Portfolio Segment [Member] | Acquired Loan [Member] | Home Equity and Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	393,000	1,019,000
Loans, current	88,684,000	108,200,000
Loans	89,077,000	109,219,000
Loans, recorded balance > 89 days and accruing	0	26,000
Retail Portfolio Segment [Member] | Acquired Loan [Member] | Home Equity and Other [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	198,000	445,000
Retail Portfolio Segment [Member] | Acquired Loan [Member] | Home Equity and Other [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	33,000	419,000
Retail Portfolio Segment [Member] | Acquired Loan [Member] | Home Equity and Other [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	162,000	155,000
Retail Portfolio Segment [Member] | Acquired Loan [Member] | 1-4 Family Mortgages [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	1,595,000	2,245,000
Loans, current	153,494,000	169,583,000
Loans	155,089,000	171,828,000
Loans, recorded balance > 89 days and accruing	0	0
Retail Portfolio Segment [Member] | Acquired Loan [Member] | 1-4 Family Mortgages [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	929,000	1,087,000
Retail Portfolio Segment [Member] | Acquired Loan [Member] | 1-4 Family Mortgages [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	136,000	408,000
Retail Portfolio Segment [Member] | Acquired Loan [Member] | 1-4 Family Mortgages [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, past due	$ 530,000	$ 750,000