Note 3 - Loans and Allowance for Loan Losses - Loans by Credit Quality Indicators (Details) - USD ($)	Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2015
Originated Loan [Member] | Grades 1-4 [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Loans	$ 476,862,000	$ 417,120,000
Originated Loan [Member] | Grades 1-4 [Member] | Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Loans	18,294,000	18,118,000
Originated Loan [Member] | Grades 1-4 [Member] | Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member]
Loans	237,640,000	230,629,000
Originated Loan [Member] | Grades 1-4 [Member] | Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member]
Loans	530,972,000	400,350,000
Originated Loan [Member] | Grades 1-4 [Member] | Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residentia lRental Loan [Member]
Loans	28,478,000	19,121,000
Originated Loan [Member] | Grades 5-7 [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Loans	190,018,000	160,454,000
Originated Loan [Member] | Grades 5-7 [Member] | Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Loans	9,599,000	10,365,000
Originated Loan [Member] | Grades 5-7 [Member] | Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member]
Loans	107,614,000	98,332,000
Originated Loan [Member] | Grades 5-7 [Member] | Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member]
Loans	107,118,000	120,404,000
Originated Loan [Member] | Grades 5-7 [Member] | Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residentia lRental Loan [Member]
Loans	16,807,000	13,806,000
Originated Loan [Member] | Grades 8-9 [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Loans	171,000	298,000
Originated Loan [Member] | Grades 8-9 [Member] | Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Loans	110,000	1,655,000
Originated Loan [Member] | Grades 8-9 [Member] | Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member]
Loans	1,069,000	1,837,000
Originated Loan [Member] | Grades 8-9 [Member] | Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member]
Loans	0	0
Originated Loan [Member] | Grades 8-9 [Member] | Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residentia lRental Loan [Member]
Loans	954,000	1,027,000
Originated Loan [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Loans	667,051,000	577,872,000
Originated Loan [Member] | Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Loans	28,003,000	30,138,000
Originated Loan [Member] | Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member]
Loans	346,323,000	330,798,000
Originated Loan [Member] | Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member]
Loans	638,090,000	520,754,000
Originated Loan [Member] | Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residentia lRental Loan [Member]
Loans	46,239,000	33,954,000
Originated Loan [Member] | Commercial Portfolio Segment [Member]
Loans	1,725,706,000	1,493,516,000	$ 1,402,320,000
Originated Loan [Member]
Loans	1,873,221,000	1,616,587,000	$ 1,519,710,000
Acquired Loan [Member] | Grades 1-4 [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Loans	43,682,000	67,978,000
Acquired Loan [Member] | Grades 1-4 [Member] | Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Loans	2,183,000	3,095,000
Acquired Loan [Member] | Grades 1-4 [Member] | Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member]
Loans	40,534,000	45,807,000
Acquired Loan [Member] | Grades 1-4 [Member] | Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member]
Loans	62,371,000	71,197,000
Acquired Loan [Member] | Grades 1-4 [Member] | Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residentia lRental Loan [Member]
Loans	40,803,000	44,763,000
Acquired Loan [Member] | Grades 5-7 [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Loans	38,201,000	47,589,000
Acquired Loan [Member] | Grades 5-7 [Member] | Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Loans	7,114,000	11,364,000
Acquired Loan [Member] | Grades 5-7 [Member] | Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member]
Loans	51,972,000	63,563,000
Acquired Loan [Member] | Grades 5-7 [Member] | Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member]
Loans	39,544,000	50,066,000
Acquired Loan [Member] | Grades 5-7 [Member] | Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residentia lRental Loan [Member]
Loans	30,470,000	35,288,000
Acquired Loan [Member] | Grades 8-9 [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Loans	1,396,000	2,864,000
Acquired Loan [Member] | Grades 8-9 [Member] | Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Loans	155,000	523,000
Acquired Loan [Member] | Grades 8-9 [Member] | Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member]
Loans	1,875,000	5,751,000
Acquired Loan [Member] | Grades 8-9 [Member] | Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member]
Loans	1,439,000	2,334,000
Acquired Loan [Member] | Grades 8-9 [Member] | Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residentia lRental Loan [Member]
Loans	591,000	998,000
Acquired Loan [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Loans	83,279,000	118,431,000
Acquired Loan [Member] | Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Loans	9,452,000	14,982,000
Acquired Loan [Member] | Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member]
Loans	94,381,000	115,121,000
Acquired Loan [Member] | Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member]
Loans	103,354,000	123,597,000
Acquired Loan [Member] | Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residentia lRental Loan [Member]
Loans	71,864,000	81,049,000
Acquired Loan [Member] | Commercial Portfolio Segment [Member]
Loans	362,330,000	453,180,000
Acquired Loan [Member]
Loans	533,156,000	661,140,000
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Loans	750,330,000	696,303,000
Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Loans	37,455,000	45,120,000
Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member]
Loans	440,704,000	445,919,000
Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member]
Loans	741,444,000	644,351,000
Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residentia lRental Loan [Member]
Loans	118,103,000	115,003,000
Commercial Portfolio Segment [Member]
Loans	2,088,036,000	1,946,696,000
Loans	$ 2,406,377,000	$ 2,277,727,000