Foreign Operations - Net Sales to External Customers by Geographic Area (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Schedule of Revenues from Geographical Segments [Line Items]
Net sales	$ 200,724	$ 182,717	$ 578,783	$ 509,938
United States
Schedule of Revenues from Geographical Segments [Line Items]
Net sales	107,546	84,756	313,029	243,801
Asia (excluding the PRC)
Schedule of Revenues from Geographical Segments [Line Items]
Net sales	29,613	36,888	79,157	91,755
Europe
Schedule of Revenues from Geographical Segments [Line Items]
Net sales	23,388	18,785	69,510	58,245
People's Republic of China (PRC)
Schedule of Revenues from Geographical Segments [Line Items]
Net sales	23,704	28,108	66,465	68,852
Latin America
Schedule of Revenues from Geographical Segments [Line Items]
Net sales	8,281	6,411	26,187	23,077
Other
Schedule of Revenues from Geographical Segments [Line Items]
Net sales	$ 8,192	$ 7,769	$ 24,435	$ 24,208