Note 12 - Pension and Postretirement Benefit Plans (Details Textual) $ in Thousands	1 Months Ended	12 Months Ended
	Jun. 30, 2019 USD ($)	Dec. 31, 2021 USD ($) Rate	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Oct. 31, 2017
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement				$ (259,000)
Period of Forecast (Year)		10 years
Minimum [Member]
Multiemployer Plans, Green Zone, Percentage (Rate) | Rate		80.00%
Multiemployer Plans, Yellow Zone, Percentage (Rate) | Rate		65.00%
Multi-employer Plan, Employer Contribution, Percentage (Rate) | Rate		5.00%
Maximum [Member]
Multiemployer Plans, Red Zone, Percentage (Rate) | Rate		65.00%
UNITED STATES | Pension Plan [Member]
Defined Benefit Plan, Plan Assets, Contributions by Employer			$ 1,000
Defined Benefit Plan, Funded (Unfunded) Status of Plan, Total		$ (12,000)	(29,000)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement				(256,000)
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Return on Assets, Next Fiscal Year (Rate) | Rate		4.00%
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year		$ 0
UNITED STATES | Pension Plan [Member] | Growth Portfolio [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage (Rate) | Rate		18.00%
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage (Rate) | Rate		18.00%
UNITED STATES | Pension Plan [Member] | Immunizing Portfolio [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage (Rate) | Rate		80.00%
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage (Rate) | Rate		80.00%
UNITED STATES | Pension Plan [Member] | Liquidity Portfolio [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage (Rate) | Rate		2.00%
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage (Rate) | Rate		2.00%
UNITED STATES | Pension Plan [Member] | Terminated Plan [Member]
Number of Plans Terminated					1
Defined Benefit Plan, Plan Assets, Contributions by Employer	$ 59,000
Defined Benefit Plan, Funded (Unfunded) Status of Plan, Total	$ 165,000
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement				256,000
Foreign Plan [Member] | Pension Plan [Member]
Defined Benefit Plan, Plan Assets, Contributions by Employer		$ 17,000	14,000
Defined Benefit Plan, Funded (Unfunded) Status of Plan, Total		(319,000)	$ (369,000)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement				$ (3,000)
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year		$ 17,000