Divestitures Divestitures - Additional Information (Details) - USD ($) $ in Thousands			3 Months Ended		6 Months Ended
	Feb. 01, 2016	Jan. 04, 2016	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Jun. 17, 2016	Dec. 31, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash proceeds from divestitures, net					$ 310,599	$ 0
Gain (loss) on sales of businesses, net			$ 974	$ 0	122,298	$ 0
Chemetall Surface Treatment
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash consideration							$ 3,200,000
Net property, plant and equipment			161,846		161,846			$ 163,643
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 (loss) 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 (loss) on sales of businesses, net					112,300
Assets held for sale, excluding discontinued operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net property, plant and equipment			3,000		3,000			$ 115,865
Magnifin Magnesiaprodukte GmbH & Co. KG
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Ownership Percentage	50.00%
Corporate | Wafer Reclaim
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain (loss) on sales of businesses, net					(1,500)
United States | Chemetall Surface Treatment
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Discrete non-cash charge			381,500		381,500
Foreign | Chemetall Surface Treatment
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Discrete non-cash charge			$ 35,200		35,200
Deferred tax liability [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Discrete non-cash charge					$ 416,700