Note 5 - Defined Benefit Plan - Defined Benefit Plan Activity (Details) - Pension Plan [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Service cost	$ 324	$ 361	$ 972	$ 1,083
Interest cost	204	184	612	552
Expected return on plan assets	(629)	(555)	(1,887)	(1,665)
Amortization of prior service cost	0	(3)	0	(9)
Recognized net actuarial loss	110	208	330	624
Net periodic benefit cost	$ 9	$ 195	$ 27	$ 585