Note 12 - Accumulated Other Comprehensive Loss - Changes in Accumulated Other Comprehensive Loss by Component (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Balance	$ 196,598	$ 167,928	$ 185,799	$ 168,051
Other comprehensive (loss) income	(1,836)	3,654	(1,627)	2,217
Balance	200,202	178,771	200,202	178,771
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Balance			(13,142)
Other comprehensive (loss) income before reclassifications			(1,971)
Amount reclassified from accumulated other comprehensive loss			0
Other comprehensive (loss) income			(1,971)
Balance	(15,113)		(15,113)
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent [Member]
Balance			19
Other comprehensive (loss) income before reclassifications			45
Amount reclassified from accumulated other comprehensive loss			0
Other comprehensive (loss) income			45
Balance	64		64
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Balance			(4,940)
Other comprehensive (loss) income before reclassifications			43
Amount reclassified from accumulated other comprehensive loss			256
Other comprehensive (loss) income			299
Balance	(4,641)		(4,641)
AOCI Attributable to Parent [Member]
Balance	(17,854)	(25,502)	(18,063)	(24,065)
Other comprehensive (loss) income before reclassifications			(1,883)
Amount reclassified from accumulated other comprehensive loss			256
Other comprehensive (loss) income			(1,627)
Balance	$ (19,690)	$ (21,848)	$ (19,690)	$ (21,848)