Note 10 - Securities Sold Under Agreements to Repurchase - Securities Sold Under Agreements to Repurchase (Details) - Securities Sold under Agreements to Repurchase [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Outstanding balance at end of period	$ 161,512		$ 161,512		$ 75,466
Weighted average interest rate at end of period	0.44%		0.44%		0.04%
Average outstanding balance during the period	$ 140,169	$ 55,673	$ 115,761	$ 51,330
Average interest rate during the period	0.16%	0.04%	0.13%	0.04%
Maximum outstanding at any month end during the period	$ 161,512	$ 63,942	$ 161,512	$ 63,942