Segment Information Revenues and Operating Net Assets by Geographical Areas (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	$ 769,970	$ 723,530	$ 705,030
Long-lived Assets	763,230	710,360	656,490
Europe [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	116,350	87,420	54,920
Long-lived Assets	225,120	110,530	53,770
Asia Pacific [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	46,350	37,920	38,920
Long-lived Assets	41,140	40,720	44,230
Other Americas [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	11,740	6,290	6,170
Long-lived Assets	19,510	18,430	7,500
Non-US [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	174,440	131,630	100,010
Long-lived Assets	285,770	169,680	105,500
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	595,530	591,900	605,020
Long-lived Assets	$ 477,460	$ 540,680	$ 550,990