Note 8 - Employee Benefit Plans - Fair Value Measurements (Details) - USD ($) $ in Thousands		Dec. 31, 2023	Dec. 31, 2022
Fair value, plan assets		$ 32,509	$ 29,746
Fair Value, Inputs, Level 1 [Member]
Fair value, plan assets		24,905	22,734
Fair Value, Inputs, Level 2 [Member]
Fair value, plan assets		7,604	7,012
Cash [Member]
Fair value, plan assets		867	415
Cash [Member] | Fair Value, Inputs, Level 1 [Member]
Fair value, plan assets		867	415
Defined Benefit Plan, Equity Securities, US [Member]
Fair value, plan assets		17,540	15,459
Defined Benefit Plan, Equity Securities, US [Member] | Fair Value, Inputs, Level 1 [Member]
Fair value, plan assets		17,540	15,459
Defined Benefit Plan, Equity Securities, Non-US [Member]
Fair value, plan assets		400	770
Defined Benefit Plan, Equity Securities, Non-US [Member] | Fair Value, Inputs, Level 1 [Member]
Fair value, plan assets		400	770
Equity Funds [Member]
Fair value, plan assets	[1]	6,098	6,090
Equity Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Fair value, plan assets	[1]	6,098	6,090
US States and Political Subdivisions Debt Securities [Member]
Fair value, plan assets		51	51
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair value, plan assets		51	51
Corporate Debt Securities [Member]
Fair value, plan assets	[2]	7,553	6,961
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair value, plan assets	[2]	$ 7,553	$ 6,961

[1] This category comprises actively managed equity funds invested in large-cap and mid-cap U.S. companies.

[2] This category represents investment grade bonds of U.S. issuers from diverse industries.