Aquisitions (Narrative) (Details) $ in Thousands, € in Millions, $ in Millions									3 Months Ended		12 Months Ended
	Oct. 01, 2018 USD ($)	Oct. 01, 2018 EUR (€)	Sep. 25, 2018 USD ($)	Sep. 25, 2018 TWD ($)	Aug. 31, 2018 USD ($)	Aug. 31, 2018 EUR (€)	Jul. 12, 2018 USD ($)	Jun. 29, 2018 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2018 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2020 USD ($)	Oct. 01, 2018 EUR (€)
Business Acquisition [Line Items]
Gain on change of control												$ 2,586
Goodwill											$ 172,212	$ 172,956	$ 175,351
Deferred tax liabilities											$ 14,866		$ 10,833
Quimicer, S.A. ("Quimicer") [Member]
Business Acquisition [Line Items]
Business acquisition, percentage of voting interests acquired	100.00%													100.00%
Business acquisition	$ 37,400	€ 32.2
Business Combination, Liabilities Arising from Contingencies, Amount Recognized	6,100													€ 5.2
Goodwill	3,000
Goodwill impairment charge									$ 3,000
Personal and real property	21,500
Deferred tax liabilities	3,000
Net working capital	$ 15,900
UWiZ Technology Co., Ltd. ("UWiZ") [Member]
Business Acquisition [Line Items]
Business acquisition, percentage of voting interests acquired			100.00%
Cash payments to acquire business			$ 26,900	$ 823.4
Amortizable intangible assets			6,600
Goodwill			7,100
Personal and real property			2,400
Deferred tax liabilities			1,700
Net working capital			$ 12,500
Ernst Diegel GmbH ("Diegel") [Member]
Business Acquisition [Line Items]
Business acquisition, percentage of voting interests acquired					100.00%
Cash payments to acquire business					$ 14,000	€ 12.1
Amortizable intangible assets					2,000
Goodwill					1,700
Personal and real property					7,000
Deferred tax liabilities					1,500
Net working capital					$ 4,800
MRA Laboratories, Inc. ("MRA") [Member]
Business Acquisition [Line Items]
Business acquisition, percentage of voting interests acquired							100.00%
Cash payments to acquire business							$ 16,000
Amortizable intangible assets							6,700
Goodwill							7,200
Personal and real property							300
Deferred tax liabilities							1,600
Net working capital							$ 3,400
PT Ferro Materials Utama ("FMU") [Member]
Business Acquisition [Line Items]
Business acquisition, percentage of voting interests acquired								66.00%			66.00%
Gain on change of control										$ 2,600	$ (2,600)
Cash payments to acquire business								$ 2,700
Forgiveness of debt								$ 9,200
PT Ferro Materials Utama ("FMU") [Member]
Business Acquisition [Line Items]
Total ownership								100.00%			100.00%