Note 9 - Non-pension Post-retirement Benefits - Pretax Amounts Recognized in Accumulated Other Comprehensive Loss (Details) - Non-Pension Post-retirement Benefit Plans [Member] - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Net actuarial loss	$ (942)	$ (5,982)
Prior service cost (credit)	(698)	(980)
Total cost in AOCI	(1,640)	(6,962)
UNITED STATES
Net actuarial loss	(134)	(5,176)
Prior service cost (credit)	(698)	(980)
Total cost in AOCI	(832)	(6,156)
Foreign Plan [Member]
Net actuarial loss	(808)	(806)
Prior service cost (credit)
Total cost in AOCI	$ (808)	$ (806)