Note 10 - Deposits - (Details Textual) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Percentage of Certificate of Deposit Maturities Year One	65.60%
Percentage of Certificate of Deposit Maturities Year Two and Thereafter	34.40%
Deposits, Total	$ 1,733,934	$ 1,055,533
Interest-bearing Domestic Deposit, Brokered	111,800	78,300
Interest Bearing Deposits Public Funds Brokered	30,900	23,100
Deposits Public Funds Non-brokered	263,800	147,700
Interest and Non-interest Bearing Deposits Liability [Member] | Top three customers [Member]
Deposits, Total	$ 146,200	$ 111,200
Percentage of Interest and Non-interest Bearing Domestic Deposits to Deposits	8.40%	10.50%