Note 10 - Benefit Plans - Defined Benefit Plans Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Supplemental Employee Retirement Plan [Member]
Benefit obligation at beginning of year	$ 12,993
Service cost on benefits earned during the period	21	$ 203
Interest cost on projected benefit obligation	637	401
Actuarial (gain) loss	229
Benefits paid	(280)
Benefit obligation at end of year	13,600	12,993
Employer contributions	280
Benefits paid	(280)
Fair value of plan assets at end of year	0
Funded status at end of year	(13,600)
Other current liabilities	(316)
Long-term pension liability	(13,284)
Net amount recognized	(13,600)
Net actuarial loss	1,964
Pension Plan [Member]
Benefit obligation at beginning of year	$ 12,993	15,523
Service cost on benefits earned during the period		203
Interest cost on projected benefit obligation		401
Actuarial (gain) loss		(3,031)
Benefits paid		(103)
Benefit obligation at end of year		12,993
Employer contributions		103
Benefits paid		(103)
Fair value of plan assets at end of year		0
Funded status at end of year		(12,993)
Other current liabilities		(129)
Long-term pension liability		(12,864)
Net amount recognized		(12,993)
Net actuarial loss		$ 1,953