Aquisitions (Narrative) (Details) $ in Thousands, € in Millions, $ in Millions																3 Months Ended		12 Months Ended
	Oct. 01, 2018 EUR (€)	Oct. 01, 2018 USD ($)	Sep. 25, 2018 USD ($)	Sep. 25, 2018 TWD ($)	Aug. 31, 2018 EUR (€)	Aug. 31, 2018 USD ($)	Jul. 12, 2018 USD ($)	Jun. 29, 2018 USD ($)	Mar. 01, 2018 USD ($)	Nov. 01, 2017 EUR (€)	Nov. 01, 2017 USD ($)	Aug. 03, 2017 USD ($)	Aug. 02, 2017 USD ($)	Apr. 24, 2017 EUR (€)	Apr. 24, 2017 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Oct. 01, 2018 USD ($)	Nov. 01, 2017 USD ($)	Apr. 24, 2017 USD ($)
Business Acquisition [Line Items]
Equity method investment, realized gain (loss) on disposal																			$ 2,586	$ 127
Acquired intangible asset amortization costs																		$ 13,000	12,600	10,100
Research and development costs																		41,000	40,100	36,200
Goodwill																		172,209	172,953	157,469
Deferred tax assets																		98,714	88,526
Deferred tax liabilities																		14,866	$ 18,606
Quimicer, S.A. ("Quimicer") [Member]
Business Acquisition [Line Items]
Business acquisition, percentage of voting interests acquired	100.00%																				100.00%
Business acquisition	€ 32.2	$ 37,400
Business Combination, Liabilities Arising from Contingencies, Amount Recognized	€ 5.2																				$ 6,100
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					€ 12.1	$ 14,000
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%
Equity method investment, realized gain (loss) on disposal																	$ 2,600		$ (2,600)
Cash payments to acquire business								$ 2,700
Forgiveness of debt								$ 9,200
Endeka Group (“Endeka”) [Member]
Business Acquisition [Line Items]
Business acquisition, percentage of voting interests acquired										100.00%												100.00%
Business acquisition										€ 72.8	$ 84,800
Acquisition costs																			500	2,500
Decrease in carrying amount of personal and real property																			5,900
Personal and real property																		15,900
Deferred tax assets																		25,900
Debt										€ 13.1												$ 15,300
Net working capital																		44,100
Noncontrolling interest																			1,100
Gardenia Quimica S.A. (“Gardenia”) [Member]
Business Acquisition [Line Items]
Business acquisition									$ 1,400			$ 3,000
Equity method investment, ownership percentage												83.50%	46.00%
Equity method investment, realized gain (loss) on disposal												$ 2,600								(2,600)
Dip Tech Ltd. (“Dip-Tech”) [Member]
Business Acquisition [Line Items]
Business acquisition, percentage of voting interests acquired													100.00%
Business acquisition													$ 77,000
Cash payments to acquire business													60,100
Business Combination, Contingent Consideration, Liability													$ 16,900
Acquisition costs																			100	$ 3,200
Amortizable intangible assets																		41,200
Goodwill																		33,500
Acquired indefinite-lived intangible assets																		5,100
Personal and real property																		3,200
Deferred tax liabilities																		7,200
Net working capital																		1,200
S.P.C. Group s.r.l. [Member]
Business Acquisition [Line Items]
Business acquisition, percentage of voting interests acquired														100.00%									100.00%
Smalti per Ceramiche, s.r.l. (together “SPC”) [Member]
Business Acquisition [Line Items]
Business acquisition, percentage of voting interests acquired														100.00%									100.00%
Business acquisition														€ 18.7	$ 20,300
Acquisition costs																			$ 1,500
Amortizable intangible assets																		6,000
Goodwill																		5,200
Personal and real property																		6,100
Deferred tax liabilities																		2,000
Debt														€ 5.7									$ 6,200
Net working capital																		$ 5,000
PT Ferro Materials Utama ("FMU") [Member]
Business Acquisition [Line Items]
Total ownership								100.00%											100.00%