Note 4 - Loans and Allowance for Loan Losses (Details) - Loans by Credit Quality Indicators (USD $)	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014
Financing Receivable, Recorded Investment [Line Items]
Loans	$ 2,120,760,000	$ 2,089,277,000
Commercial and Industrial [Member] | Originated Loan [Member] | Grade 1 - 4 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	317,742,000	266,631,000
Commercial and Industrial [Member] | Originated Loan [Member] | Grade 5 - 7 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	108,649,000	109,639,000
Commercial and Industrial [Member] | Originated Loan [Member] | Grade 8 - 9 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	7,820,000	8,300,000
Commercial and Industrial [Member] | Originated Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	434,211,000	384,570,000
Commercial and Industrial [Member] | Acquired Loan [Member] | Grade 1 - 4 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	67,795,000	72,411,000
Commercial and Industrial [Member] | Acquired Loan [Member] | Grade 5 - 7 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	82,344,000	90,320,000
Commercial and Industrial [Member] | Acquired Loan [Member] | Grade 8 - 9 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	3,325,000	3,306,000
Commercial and Industrial [Member] | Acquired Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	153,464,000	166,037,000
Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	587,675,000	550,607,000
Vacant Land and Land Development and Residential Construction Loan [Member] | Originated Loan [Member] | Grade 1 - 4 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	17,255,000	11,242,000
Vacant Land and Land Development and Residential Construction Loan [Member] | Originated Loan [Member] | Grade 5 - 7 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	16,430,000	16,375,000
Vacant Land and Land Development and Residential Construction Loan [Member] | Originated Loan [Member] | Grade 8 - 9 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	2,263,000	2,209,000
Vacant Land and Land Development and Residential Construction Loan [Member] | Originated Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	35,948,000	29,826,000
Vacant Land and Land Development and Residential Construction Loan [Member] | Acquired Loan [Member] | Grade 1 - 4 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	5,635,000	5,875,000
Vacant Land and Land Development and Residential Construction Loan [Member] | Acquired Loan [Member] | Grade 5 - 7 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	12,844,000	14,472,000
Vacant Land and Land Development and Residential Construction Loan [Member] | Acquired Loan [Member] | Grade 8 - 9 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,623,000	1,801,000
Vacant Land and Land Development and Residential Construction Loan [Member] | Acquired Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	20,102,000	22,148,000
Vacant Land and Land Development and Residential Construction Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	56,050,000	51,974,000
Real Estate Owner Occupied Loan [Member] | Originated Loan [Member] | Grade 1 - 4 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	203,094,000	190,656,000
Real Estate Owner Occupied Loan [Member] | Originated Loan [Member] | Grade 5 - 7 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	81,245,000	83,123,000
Real Estate Owner Occupied Loan [Member] | Originated Loan [Member] | Grade 8 - 9 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	18,040,000	17,979,000
Real Estate Owner Occupied Loan [Member] | Originated Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	302,379,000	291,758,000
Real Estate Owner Occupied Loan [Member] | Acquired Loan [Member] | Grade 1 - 4 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	39,732,000	39,496,000
Real Estate Owner Occupied Loan [Member] | Acquired Loan [Member] | Grade 5 - 7 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	82,819,000	92,212,000
Real Estate Owner Occupied Loan [Member] | Acquired Loan [Member] | Grade 8 - 9 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	7,065,000	6,922,000
Real Estate Owner Occupied Loan [Member] | Acquired Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	129,616,000	138,630,000
Real Estate Owner Occupied Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	431,995,000	430,388,000
Real Estate Non Owner Occupied Loan [Member] | Originated Loan [Member] | Grade 1 - 4 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	295,402,000	285,035,000
Real Estate Non Owner Occupied Loan [Member] | Originated Loan [Member] | Grade 5 - 7 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	117,222,000	113,982,000
Real Estate Non Owner Occupied Loan [Member] | Originated Loan [Member] | Grade 8 - 9 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	10,757,000	11,960,000
Real Estate Non Owner Occupied Loan [Member] | Originated Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	423,381,000	410,977,000
Real Estate Non Owner Occupied Loan [Member] | Acquired Loan [Member] | Grade 1 - 4 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	67,500,000	65,886,000
Real Estate Non Owner Occupied Loan [Member] | Acquired Loan [Member] | Grade 5 - 7 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	71,656,000	78,103,000
Real Estate Non Owner Occupied Loan [Member] | Acquired Loan [Member] | Grade 8 - 9 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	3,615,000	4,608,000
Real Estate Non Owner Occupied Loan [Member] | Acquired Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	142,771,000	148,597,000
Real Estate Non Owner Occupied Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	566,152,000	559,574,000
Real Estate Multi Family and Residential Rental Loan [Member] | Originated Loan [Member] | Grade 1 - 4 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	12,632,000	12,394,000
Real Estate Multi Family and Residential Rental Loan [Member] | Originated Loan [Member] | Grade 5 - 7 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	20,947,000	22,282,000
Real Estate Multi Family and Residential Rental Loan [Member] | Originated Loan [Member] | Grade 8 - 9 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,343,000	1,382,000
Real Estate Multi Family and Residential Rental Loan [Member] | Originated Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	34,922,000	36,058,000
Real Estate Multi Family and Residential Rental Loan [Member] | Acquired Loan [Member] | Grade 1 - 4 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	35,725,000	35,858,000
Real Estate Multi Family and Residential Rental Loan [Member] | Acquired Loan [Member] | Grade 5 - 7 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	45,230,000	49,781,000
Real Estate Multi Family and Residential Rental Loan [Member] | Acquired Loan [Member] | Grade 8 - 9 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,600,000	1,063,000
Real Estate Multi Family and Residential Rental Loan [Member] | Acquired Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	82,555,000	86,702,000
Real Estate Multi Family and Residential Rental Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	117,477,000	122,760,000
Originated Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,328,713,000	1,246,116,000	1,066,796,000
Acquired Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	$ 792,047,000	$ 843,161,000