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, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Balance		$ 167,928	$ 180,276	$ 168,051	$ 176,470
Other comprehensive income (loss)		3,654	(2,524)	2,217	(2,743)
Balance		178,771	170,640	178,771	170,640
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Balance				(20,032)
Other comprehensive income (loss) before reclassifications				2,020
Amount reclassified from accumulated other comprehensive income (loss)				0
Other comprehensive income (loss)				2,020
Balance		(18,012)		(18,012)
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent [Member]
Balance				12
Other comprehensive income (loss) before reclassifications				(1)
Amount reclassified from accumulated other comprehensive income (loss)				0
Other comprehensive income (loss)				(1)
Balance		11		11
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Balance				(4,045)
Other comprehensive income (loss) before reclassifications				95
Amount reclassified from accumulated other comprehensive income (loss)	[1]			103
Other comprehensive income (loss)				198
Balance		(3,847)		(3,847)
AOCI Attributable to Parent [Member]
Balance		(25,502)	(25,521)	(24,065)	(24,838)
Other comprehensive income (loss) before reclassifications				2,114
Amount reclassified from accumulated other comprehensive income (loss)				103
Other comprehensive income (loss)				2,217
Balance		$ (21,848)	$ (28,045)	$ (21,848)	$ (28,045)

[1] This reclassification relates to the amortization of prior service costs and gains/losses associated with the Company's SERP Plan. This expense is allocated between cost of sales and selling, general and administrative expense based upon the employment classification of the plan participants.