Note 2 - Acquisitions and Divestitures - Net Cash (Received) Paid in Acquisitions and Divestitures (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016	Dec. 31, 2015
Goodwill	$ 92,744	$ 95,779	[1]	$ 95,779	$ 100,486
Non-cash sales price	1,603
Net cash received in acquisitions and divestitures	(10)			(29,716)
Acquisitions in 2018 [Member]
Loans
Premises and equipment
Other assets
Other intangible assets
Deposits
Other liabilities
Goodwill
Total purchase price
Non-cash purchase price
Cash acquired
Net cash paid in acquisitions
Book value of assets sold	(1,685)
Book value of liabilities sold	37
Sales price in excess of net liabilities assumed
Total sales price	(1,648)
Cash sold	35
Non-cash sales price	1,603
Amount due remaining on books
Net cash received in divestitures	(10)
Net cash received in acquisitions and divestitures	$ (10)
Acquisitions in 2017 [Member]
Loans
Premises and equipment
Other assets
Other intangible assets
Deposits
Other liabilities
Goodwill
Total purchase price
Non-cash purchase price
Cash acquired
Net cash paid in acquisitions
Book value of assets sold
Book value of liabilities sold
Sales price in excess of net liabilities assumed
Total sales price
Cash sold
Non-cash sales price
Amount due remaining on books
Net cash received in divestitures
Net cash received in acquisitions and divestitures
Acquisitions in 2016 [Member]
Loans				149,122
Premises and equipment				4,829
Other assets				448
Other intangible assets				3,842
Deposits				(134,307)
Other liabilities				(75)
Goodwill				2,446
Total purchase price				26,305
Non-cash purchase price
Cash acquired
Net cash paid in acquisitions				26,305
Book value of assets sold				(165,742)
Book value of liabilities sold				111,198
Sales price in excess of net liabilities assumed				(3,682)
Total sales price				(58,226)
Cash sold
Non-cash sales price
Amount due remaining on books				2,205
Net cash received in divestitures				(56,021)
Net cash received in acquisitions and divestitures				$ (29,716)

[1] Derived from audited financial statements