Note 12 - Accumulated Other Comprehensive Loss - Reclassification of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Cost of sales	$ 59,751	$ 47,252	$ 176,808	$ 109,292
Net income	10,747	27,801	15,886	20,164
Revenue from Contract with Customer, Including Assessed Tax	75,226	52,455	207,072	114,605
Associated income tax (expense) benefit	(2,529)	3,456	(3,167)	3,836
Reclassification out of Accumulated Other Comprehensive Income [Member]
Net income		9	(1)	7
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Cost of sales	(2)		(8)
Net income	(2)		(8)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member]
Net income	2	9	7	7
Revenue from Contract with Customer, Including Assessed Tax	3	12	10	9
Associated income tax (expense) benefit	$ (1)	$ (3)	$ (3)	$ (2)