Goodwill and Other Intangibles - Changes in Goodwill (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Goodwill [Line Items]
Goodwill classified as assets held for sale		$ 14,400
Goodwill [Roll Forward]
Balance at beginning of period	$ 1,610,355
Foreign currency translation adjustments and other	(19,449)
Balance at end of period	1,590,906
Reportable Segments | Lithium
Goodwill [Roll Forward]
Balance at beginning of period	1,389,089
Foreign currency translation adjustments and other	(15,766)
Balance at end of period	1,373,323
Reportable Segments | Bromine Specialties
Goodwill [Roll Forward]
Balance at beginning of period	20,319
Foreign currency translation adjustments and other	0
Balance at end of period	20,319
Reportable Segments | Catalysts
Goodwill [Roll Forward]
Balance at beginning of period	194,361
Foreign currency translation adjustments and other	(3,683)
Balance at end of period	190,678
Reportable Segments | All Other
Goodwill [Roll Forward]
Balance at beginning of period	6,586
Foreign currency translation adjustments and other	0
Balance at end of period	$ 6,586