Note 4 - Loans and Leases - Aging of the Recorded Investment in Loans (Details) - USD ($) $ in Thousands		Sep. 30, 2019	Dec. 31, 2018
Current		$ 2,845,527	$ 2,537,627
Past due		11,137	10,544
Loans	[1]	2,856,664	2,548,171
Financial Asset, 30 to 59 Days Past Due [Member]
Past due		6,683	5,112
Financial Asset, 60 to 89 Days Past Due [Member]
Past due		1,245	2,076
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Past due		3,209	3,356
Commercial and Industrial Portfolio Segment [Member]
Current		874,576	832,923
Past due		1,551	601
Loans		876,127	833,524
Commercial and Industrial Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Past due		465	197
Commercial and Industrial Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Past due		900	200
Commercial and Industrial Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Past due		186	204
Construction and Development Excluding Undeveloped Land Portfolio Segment [Member]
Current		248,296	224,732
Past due		0	318
Loans	[2]	248,296	225,050
Construction and Development Excluding Undeveloped Land Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Past due		0	0
Construction and Development Excluding Undeveloped Land Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Past due		0	0
Construction and Development Excluding Undeveloped Land Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Past due		0	318
Undevelopment Land Portfolio Segment [Member]
Current		35,169	29,552
Past due		0	540
Loans		35,169	30,092
Undevelopment Land Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Past due		0	66
Undevelopment Land Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Past due		0	0
Undevelopment Land Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Past due		0	474
Real Estate Mortgage Portfolio Segment [Member]
Current		1,643,964	1,402,362
Past due		9,540	9,085
Loans		1,653,504	1,411,447
Real Estate Mortgage Portfolio Segment [Member] | Commercial Investment [Member]
Current		723,028	586,884
Past due		4,503	1,726
Loans		727,531	588,610
Real Estate Mortgage Portfolio Segment [Member] | Owner Occupied Commercial [Member]
Current		468,699	421,143
Past due		1,979	5,230
Loans		470,678	426,373
Real Estate Mortgage Portfolio Segment [Member] | One to Four Family Residential [Member]
Current		329,140	274,547
Past due		2,607	1,470
Loans		331,747	276,017
Real Estate Mortgage Portfolio Segment [Member] | Home Equity First Lien [Member]
Current		50,881	49,321
Past due		134	179
Loans		51,015	49,500
Real Estate Mortgage Portfolio Segment [Member] | Home Equity Junior Lien [Member]
Current		72,216	70,467
Past due		317	480
Loans		72,533	70,947
Real Estate Mortgage Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Past due		6,172	4,849
Real Estate Mortgage Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Investment [Member]
Past due		3,352	1,382
Real Estate Mortgage Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member] | Owner Occupied Commercial [Member]
Past due		478	2,732
Real Estate Mortgage Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member] | One to Four Family Residential [Member]
Past due		2,159	374
Real Estate Mortgage Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member] | Home Equity First Lien [Member]
Past due		134	179
Real Estate Mortgage Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member] | Home Equity Junior Lien [Member]
Past due		49	182
Real Estate Mortgage Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Past due		345	1,876
Real Estate Mortgage Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Investment [Member]
Past due		14	107
Real Estate Mortgage Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member] | Owner Occupied Commercial [Member]
Past due		92	1,377
Real Estate Mortgage Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member] | One to Four Family Residential [Member]
Past due		239	336
Real Estate Mortgage Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member] | Home Equity First Lien [Member]
Past due		0	0
Real Estate Mortgage Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member] | Home Equity Junior Lien [Member]
Past due		0	56
Real Estate Mortgage Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Past due		3,023	2,360
Real Estate Mortgage Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Investment [Member]
Past due		1,137	237
Real Estate Mortgage Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Owner Occupied Commercial [Member]
Past due		1,409	1,121
Real Estate Mortgage Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | One to Four Family Residential [Member]
Past due		209	760
Real Estate Mortgage Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Home Equity First Lien [Member]
Past due		0	0
Real Estate Mortgage Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Home Equity Junior Lien [Member]
Past due		268	242
Consumer Portfolio Segment [Member]
Current		43,522	48,058
Past due		46	0
Loans		43,568	48,058
Consumer Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Past due		46	0
Consumer Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Past due		0	0
Consumer Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Past due		$ 0	$ 0

[1] Total loans are presented inclusive of premiums, discounts, and net loan origination fees and costs.

[2] Consists of land acquired for development by the borrower, but for which no development has yet taken place.