Note 4 - Loans and Allowance for Loan Losses (Details) - Loans by Credit Quality Indicators - USD ($)	Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2014
Financing Receivable, Recorded Investment [Line Items]
Loans	$ 2,171,832,000	$ 2,089,277,000
Originated Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,429,623,000	1,246,116,000	$ 1,145,097,000
Acquired Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	742,209,000	843,161,000
Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,820,431,000	1,715,303,000
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [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 [Line Items]
Loans	47,622,000	51,974,000
Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	422,354,000	430,388,000
Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member]
Financing Receivable, Recorded Investment [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 [Line Items]
Loans	124,658,000	122,760,000
Commercial Portfolio Segment [Member] | Originated Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,322,388,000	1,153,189,000	$ 1,076,609,000
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	487,440,000	384,570,000
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Commercial and Industrial [Member] | Grade 1 - 4 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	348,542,000	266,631,000
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Commercial and Industrial [Member] | Grade 5 - 7 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	136,948,000	109,639,000
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Commercial and Industrial [Member] | Grade 8 - 9 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,950,000	8,300,000
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	28,853,000	29,826,000
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Vacant Land and Land Development and Residential Construction Loan [Member] | Grade 1 - 4 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	15,243,000	11,242,000
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Vacant Land and Land Development and Residential Construction Loan [Member] | Grade 5 - 7 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	11,426,000	16,375,000
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Vacant Land and Land Development and Residential Construction Loan [Member] | Grade 8 - 9 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	2,184,000	2,209,000
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Owner Occupied Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	297,694,000	291,758,000
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Owner Occupied Loan [Member] | Grade 1 - 4 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	211,066,000	190,656,000
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Owner Occupied Loan [Member] | Grade 5 - 7 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	83,907,000	83,123,000
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Owner Occupied Loan [Member] | Grade 8 - 9 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	2,721,000	17,979,000
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Non Owner Occupied Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	469,433,000	410,977,000
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Non Owner Occupied Loan [Member] | Grade 1 - 4 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	342,030,000	285,035,000
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Non Owner Occupied Loan [Member] | Grade 5 - 7 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	121,726,000	113,982,000
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Non Owner Occupied Loan [Member] | Grade 8 - 9 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	5,677,000	11,960,000
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Multi Family and Residential Rental Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	38,968,000	36,058,000
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Multi Family and Residential Rental Loan [Member] | Grade 1 - 4 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	16,044,000	12,394,000
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Multi Family and Residential Rental Loan [Member] | Grade 5 - 7 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	21,619,000	22,282,000
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Multi Family and Residential Rental Loan [Member] | Grade 8 - 9 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,305,000	1,382,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	498,043,000	562,114,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	134,633,000	166,037,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Commercial and Industrial [Member] | Grade 1 - 4 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	59,441,000	72,411,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Commercial and Industrial [Member] | Grade 5 - 7 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	71,999,000	90,320,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Commercial and Industrial [Member] | Grade 8 - 9 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	3,193,000	3,306,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	18,769,000	22,148,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Vacant Land and Land Development and Residential Construction Loan [Member] | Grade 1 - 4 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	5,382,000	5,875,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Vacant Land and Land Development and Residential Construction Loan [Member] | Grade 5 - 7 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	12,177,000	14,472,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Vacant Land and Land Development and Residential Construction Loan [Member] | Grade 8 - 9 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,210,000	1,801,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Owner Occupied Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	124,660,000	138,630,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Owner Occupied Loan [Member] | Grade 1 - 4 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	44,922,000	39,496,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Owner Occupied Loan [Member] | Grade 5 - 7 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	73,383,000	92,212,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Owner Occupied Loan [Member] | Grade 8 - 9 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	6,355,000	6,922,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Non Owner Occupied Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	134,291,000	148,597,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Non Owner Occupied Loan [Member] | Grade 1 - 4 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	67,258,000	65,886,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Non Owner Occupied Loan [Member] | Grade 5 - 7 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	63,716,000	78,103,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Non Owner Occupied Loan [Member] | Grade 8 - 9 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	3,317,000	4,608,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Multi Family and Residential Rental Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	85,690,000	86,702,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Multi Family and Residential Rental Loan [Member] | Grade 1 - 4 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	41,488,000	35,858,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Multi Family and Residential Rental Loan [Member] | Grade 5 - 7 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	40,329,000	49,781,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Multi Family and Residential Rental Loan [Member] | Grade 8 - 9 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	$ 3,873,000	$ 1,063,000