Note 18 - Commitments and Contingencies (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Maximum performance guarantee term	1 year
Liability for potential guarantee obligations	$ 0	$ 0
Sale of mortgage loans in the secondary market	1,300	645
Loans sold with recourse provisions	12,400	300
Amount of uninsured cash	52,600	42,900
Money market funds at carrying value	96,600	136,000
Standby Letters of Credit [Member]
Other commitment	20,300	17,300
Commitments to Extend Credit [Member]
Other commitment	$ 1,200,000	$ 791,600