Divestitures - Additional Information (Details) - USD ($) $ in Thousands				3 Months Ended						12 Months Ended
	Dec. 14, 2016	Feb. 01, 2016	Jan. 04, 2016	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Jun. 30, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash proceeds from divestitures, net										$ 413,569	$ 6,857	$ 3,325,571
Gain on sales of businesses, net				$ (8,277)	$ 0	$ 218,705	$ 0			210,428	0	122,298
Amounts reclassified from accumulated other comprehensive loss										(9,368)	(2,019)	(84,371)
Actuarial losses				$ 14,000				$ (11,400)
Assets held for sale, excluding discontinued operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash proceeds from divestitures, net										413,600
Gain on sales of businesses, net										210,400
Chemetall Surface Treatment
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash proceeds from divestitures, net	$ 3,100,000
Gain on sale of business, before income taxes												(387,980)
Gain on sale of business, net of tax												135,000
Working capital settlement									$ 6,900
Actuarial losses												(8,500)
Tax expense on gain on sale of business												253,000
Metal Sulfides Business
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash proceeds from divestitures, net			$ 137,000
Gain on sales of businesses, net												11,500
Mineral Flame Retardants and Specialty Chemicals Businesses
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash proceeds from divestitures, net		$ 187,000
Gain on sales of businesses, net												112,300
Corporate | Wafer Reclaim
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on sales of businesses, net												(1,500)
Foreign Currency Translation
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Amounts reclassified from accumulated other comprehensive loss										$ 0	$ 0	$ (81,421)