Note 8 - Pension (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets	6.50%
UNITED STATES
Defined Contribution Plan, Cost	$ 3,900	$ 3,800
Foreign Plan [Member]
Defined Contribution Plan, Cost	2,000	2,000
Pension Plan [Member]
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	$ (37,698)	$ 31,537
Pension Plan [Member] | UNITED STATES
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets	6.50%	7.00%
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	$ (28,820)	$ 28,481
Pension Plan [Member] | Foreign Plan [Member]
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	$ (8,878)	$ 3,056
U.S. Salaried Plan [Member]
Defined Contribution Plan, Employer Matching Contribution, Percent of Match	100.00%
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay	6.00%
U.S. Salaried Plan [Member] | Minimum [Member]
Defined Benefit Plan, Cash Balance Interest Crediting Rate	5.00%
US Hourly Plan [Member]
Defined Contribution Plan, Employer Matching Contribution, Percent of Match	50.00%
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay	6.00%