Note 14 - Segment Information - Schedule of Reconciliation of Consolidated Operating Profit to Income Before Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Gross sales by segment
Total reported gross sales	$ 104,231	$ 112,233	$ 390,575	$ 350,431
Operating profit/(loss) by segment
Total reported operating profit/(loss)	6,632	25,543	81,665	88,109
API [Member]
Gross sales by segment
Total reported gross sales	99,445	112,233	385,789	350,431
Operating profit/(loss) by segment
Total reported operating profit/(loss)	16,872	31,932	101,436	106,779
FDF [Member]
Gross sales by segment
Total reported gross sales	4,786		4,786
Operating profit/(loss) by segment
Total reported operating profit/(loss)	114		114
Total Segment [Member]
Operating profit/(loss) by segment
Total reported operating profit/(loss)	16,986	31,932	101,550	106,779
Corporate [Member]
Operating profit/(loss) by segment
Total reported operating profit/(loss)	$ (10,354)	$ (6,389)	$ (19,885)	$ (18,670)