Note 9 - Employee Retirement Plans - Pension Plan Measured at Fair Value (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Fair value of plan assets	$ 45,378	$ 56,779	$ 56,495	$ 59,625
Pension Plan [Member] | Change In Plan Assets [Member]
Fair value of plan assets	45,377	56,779
Pension Plan [Member] | Fair Value, Inputs, Level 1 [Member] | Change In Plan Assets [Member]
Fair value of plan assets	30,281	55,868
Pension Plan [Member] | Fair Value, Inputs, Level 2 [Member] | Change In Plan Assets [Member]
Fair value of plan assets	11,894	911
Pension Plan [Member] | Fair Value, Inputs, Level 3 [Member] | Change In Plan Assets [Member]
Fair value of plan assets	3,202	0
Pension Plan [Member] | Fair Value Measured at Net Asset Value Per Share [Member] | Change In Plan Assets [Member]
Fair value of plan assets	0	0
Pension Plan [Member] | Defined Benefit Plan, Equity Securities [Member]
Fair value of plan assets	31,196	36,240
Pension Plan [Member] | Defined Benefit Plan, Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair value of plan assets	26,847	36,240
Pension Plan [Member] | Defined Benefit Plan, Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair value of plan assets	1,147	0
Pension Plan [Member] | Defined Benefit Plan, Equity Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value of plan assets	3,202	0
Pension Plan [Member] | Defined Benefit Plan, Equity Securities [Member] | Fair Value Measured at Net Asset Value Per Share [Member]
Fair value of plan assets	0	0
Pension Plan [Member] | Defined Benefit Plan, Debt Security [Member]
Fair value of plan assets	12,928	19,628
Pension Plan [Member] | Defined Benefit Plan, Debt Security [Member] | Fair Value, Inputs, Level 1 [Member]
Fair value of plan assets	3,434	19,628
Pension Plan [Member] | Defined Benefit Plan, Debt Security [Member] | Fair Value, Inputs, Level 2 [Member]
Fair value of plan assets	9,494	0
Pension Plan [Member] | Defined Benefit Plan, Debt Security [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value of plan assets	0	0
Pension Plan [Member] | Defined Benefit Plan, Debt Security [Member] | Fair Value Measured at Net Asset Value Per Share [Member]
Fair value of plan assets	0	0
Pension Plan [Member] | Defined Benefit Plan, Cash and Cash Equivalents [Member]
Fair value of plan assets	1,253	911
Pension Plan [Member] | Defined Benefit Plan, Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member]
Fair value of plan assets	0	0
Pension Plan [Member] | Defined Benefit Plan, Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member]
Fair value of plan assets	1,253	911
Pension Plan [Member] | Defined Benefit Plan, Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value of plan assets	0	0
Pension Plan [Member] | Defined Benefit Plan, Cash and Cash Equivalents [Member] | Fair Value Measured at Net Asset Value Per Share [Member]
Fair value of plan assets	$ 0	$ 0