Operating Segments and Geographic Information (Operations by Geographic Area) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Long-Lived Assets	$ 660,576	$ 682,123
United States
Segment Reporting Information [Line Items]
Long-Lived Assets	432,497	469,234
China
Segment Reporting Information [Line Items]
Long-Lived Assets	48,850	55,078
Germany
Segment Reporting Information [Line Items]
Long-Lived Assets	133,168	120,869
Other
Segment Reporting Information [Line Items]
Long-Lived Assets	$ 46,061	$ 36,942