Note 3 - Loans and Allowance for Loan Losses - Loans by Credit Quality Indicators (Details) - USD ($)	Jun. 30, 2019	Dec. 31, 2018
Loans	$ 2,881,493,000	$ 2,753,085,000
Originated Loan [Member]
Loans	2,609,686,000	2,452,446,000
Acquired Loan [Member]
Loans	271,807,000	300,639,000
Commercial Portfolio Segment [Member]
Loans	2,464,555,000	2,360,106,000
Commercial Portfolio Segment [Member] \| Originated Loan [Member]
Loans	2,274,931,000	2,151,998,000
Commercial Portfolio Segment [Member] \| Acquired Loan [Member]
Loans	189,624,000	208,108,000
Commercial Portfolio Segment [Member] \| Commercial and Industrial [Member]
Loans	881,196,000	822,723,000
Commercial Portfolio Segment [Member] \| Commercial and Industrial [Member] \| Originated Loan [Member]
Loans	833,589,000	768,698,000
Commercial Portfolio Segment [Member] \| Commercial and Industrial [Member] \| Acquired Loan [Member]
Loans	47,607,000	54,025,000
Commercial Portfolio Segment [Member] \| Vacant Land and Land Development and Residential Construction Loan [Member]
Loans	45,158,000	44,885,000
Commercial Portfolio Segment [Member] \| Vacant Land and Land Development and Residential Construction Loan [Member] \| Originated Loan [Member]
Loans	40,609,000	39,950,000
Commercial Portfolio Segment [Member] \| Vacant Land and Land Development and Residential Construction Loan [Member] \| Acquired Loan [Member]
Loans	4,549,000	4,935,000
Commercial Portfolio Segment [Member] \| Real Estate Owner Occupied Loan [Member]
Loans	556,868,000	548,619,000
Commercial Portfolio Segment [Member] \| Real Estate Owner Occupied Loan [Member] \| Originated Loan [Member]
Loans	513,016,000	500,188,000
Commercial Portfolio Segment [Member] \| Real Estate Owner Occupied Loan [Member] \| Acquired Loan [Member]
Loans	43,852,000	48,431,000
Commercial Portfolio Segment [Member] \| Real Estate Non Owner Occupied Loan [Member]
Loans	852,844,000	816,282,000
Commercial Portfolio Segment [Member] \| Real Estate Non Owner Occupied Loan [Member] \| Originated Loan [Member]
Loans	786,666,000	745,127,000
Commercial Portfolio Segment [Member] \| Real Estate Non Owner Occupied Loan [Member] \| Acquired Loan [Member]
Loans	66,178,000	71,155,000
Commercial Portfolio Segment [Member] \| Real Estate Multi Family and Residential Rental Loan [Member]
Loans	128,489,000	127,597,000
Commercial Portfolio Segment [Member] \| Real Estate Multi Family and Residential Rental Loan [Member] \| Originated Loan [Member]
Loans	101,051,000	98,035,000
Commercial Portfolio Segment [Member] \| Real Estate Multi Family and Residential Rental Loan [Member] \| Acquired Loan [Member]
Loans	27,438,000	29,562,000
Grades 1-4 [Member] \| Commercial Portfolio Segment [Member] \| Commercial and Industrial [Member] \| Originated Loan [Member]
Loans	521,211,000	508,611,000
Grades 1-4 [Member] \| Commercial Portfolio Segment [Member] \| Commercial and Industrial [Member] \| Acquired Loan [Member]
Loans	28,882,000	34,678,000
Grades 1-4 [Member] \| Commercial Portfolio Segment [Member] \| Vacant Land and Land Development and Residential Construction Loan [Member] \| Originated Loan [Member]
Loans	24,520,000	28,170,000
Grades 1-4 [Member] \| Commercial Portfolio Segment [Member] \| Vacant Land and Land Development and Residential Construction Loan [Member] \| Acquired Loan [Member]
Loans	1,126,000	1,246,000
Grades 1-4 [Member] \| Commercial Portfolio Segment [Member] \| Real Estate Owner Occupied Loan [Member] \| Originated Loan [Member]
Loans	320,067,000	325,459,000
Grades 1-4 [Member] \| Commercial Portfolio Segment [Member] \| Real Estate Owner Occupied Loan [Member] \| Acquired Loan [Member]
Loans	19,972,000	21,595,000
Grades 1-4 [Member] \| Commercial Portfolio Segment [Member] \| Real Estate Non Owner Occupied Loan [Member] \| Originated Loan [Member]
Loans	544,164,000	526,445,000
Grades 1-4 [Member] \| Commercial Portfolio Segment [Member] \| Real Estate Non Owner Occupied Loan [Member] \| Acquired Loan [Member]
Loans	51,606,000	54,401,000
Grades 1-4 [Member] \| Commercial Portfolio Segment [Member] \| Real Estate Multi Family and Residential Rental Loan [Member] \| Originated Loan [Member]
Loans	72,767,000	75,051,000
Grades 1-4 [Member] \| Commercial Portfolio Segment [Member] \| Real Estate Multi Family and Residential Rental Loan [Member] \| Acquired Loan [Member]
Loans	16,409,000	16,050,000
Grades 5-7 [Member] \| Commercial Portfolio Segment [Member] \| Commercial and Industrial [Member] \| Originated Loan [Member]
Loans	288,248,000	238,942,000
Grades 5-7 [Member] \| Commercial Portfolio Segment [Member] \| Commercial and Industrial [Member] \| Acquired Loan [Member]
Loans	18,213,000	19,122,000
Grades 5-7 [Member] \| Commercial Portfolio Segment [Member] \| Vacant Land and Land Development and Residential Construction Loan [Member] \| Originated Loan [Member]
Loans	16,001,000	11,686,000
Grades 5-7 [Member] \| Commercial Portfolio Segment [Member] \| Vacant Land and Land Development and Residential Construction Loan [Member] \| Acquired Loan [Member]
Loans	3,176,000	3,431,000
Grades 5-7 [Member] \| Commercial Portfolio Segment [Member] \| Real Estate Owner Occupied Loan [Member] \| Originated Loan [Member]
Loans	190,466,000	163,455,000
Grades 5-7 [Member] \| Commercial Portfolio Segment [Member] \| Real Estate Owner Occupied Loan [Member] \| Acquired Loan [Member]
Loans	22,750,000	25,485,000
Grades 5-7 [Member] \| Commercial Portfolio Segment [Member] \| Real Estate Non Owner Occupied Loan [Member] \| Originated Loan [Member]
Loans	242,415,000	218,682,000
Grades 5-7 [Member] \| Commercial Portfolio Segment [Member] \| Real Estate Non Owner Occupied Loan [Member] \| Acquired Loan [Member]
Loans	14,404,000	16,687,000
Grades 5-7 [Member] \| Commercial Portfolio Segment [Member] \| Real Estate Multi Family and Residential Rental Loan [Member] \| Originated Loan [Member]
Loans	28,109,000	22,798,000
Grades 5-7 [Member] \| Commercial Portfolio Segment [Member] \| Real Estate Multi Family and Residential Rental Loan [Member] \| Acquired Loan [Member]
Loans	10,987,000	13,460,000
Grades 8-9 [Member] \| Commercial Portfolio Segment [Member] \| Commercial and Industrial [Member] \| Originated Loan [Member]
Loans	24,130,000	21,145,000
Grades 8-9 [Member] \| Commercial Portfolio Segment [Member] \| Commercial and Industrial [Member] \| Acquired Loan [Member]
Loans	512,000	225,000
Grades 8-9 [Member] \| Commercial Portfolio Segment [Member] \| Vacant Land and Land Development and Residential Construction Loan [Member] \| Originated Loan [Member]
Loans	88,000	94,000
Grades 8-9 [Member] \| Commercial Portfolio Segment [Member] \| Vacant Land and Land Development and Residential Construction Loan [Member] \| Acquired Loan [Member]
Loans	247,000	258,000
Grades 8-9 [Member] \| Commercial Portfolio Segment [Member] \| Real Estate Owner Occupied Loan [Member] \| Originated Loan [Member]
Loans	2,483,000	11,274,000
Grades 8-9 [Member] \| Commercial Portfolio Segment [Member] \| Real Estate Owner Occupied Loan [Member] \| Acquired Loan [Member]
Loans	1,130,000	1,351,000
Grades 8-9 [Member] \| Commercial Portfolio Segment [Member] \| Real Estate Non Owner Occupied Loan [Member] \| Originated Loan [Member]
Loans	87,000	0
Grades 8-9 [Member] \| Commercial Portfolio Segment [Member] \| Real Estate Non Owner Occupied Loan [Member] \| Acquired Loan [Member]
Loans	168,000	67,000
Grades 8-9 [Member] \| Commercial Portfolio Segment [Member] \| Real Estate Multi Family and Residential Rental Loan [Member] \| Originated Loan [Member]
Loans	175,000	186,000
Grades 8-9 [Member] \| Commercial Portfolio Segment [Member] \| Real Estate Multi Family and Residential Rental Loan [Member] \| Acquired Loan [Member]
Loans	$ 42,000	$ 52,000

Note 3 - Loans and Allowance for Loan Losses - Loans by Credit Quality Indicators (Details) - USD ($)

Jun. 30, 2019

Dec. 31, 2018

Loans

$ 2,881,493,000

$ 2,753,085,000

Originated Loan [Member]

Loans

2,609,686,000

2,452,446,000

Acquired Loan [Member]

Loans