Segment Information, Net Sales - Domestic vs. Foreign (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Segment Information [Abstract]
Net sales	$ 104,174	$ 96,800	$ 299,826	$ 281,767
Reportable Geographical Component [Member] | Domestic [Member]
Segment Information [Abstract]
Net sales	100,492	91,236	290,050	271,521
Reportable Geographical Component [Member] | Foreign [Member]
Segment Information [Abstract]
Net sales	$ 3,682	$ 5,564	$ 9,776	$ 10,246