Goodwill and Other Intangibles - Changes in Goodwill (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2019 USD ($)
Goodwill [Roll Forward]
Balance at beginning of period	$ 1,567,169
Foreign currency translation adjustments	(32,928)
Balance at end of period	1,534,241
Reportable Segments | Lithium
Goodwill [Roll Forward]
Balance at beginning of period	1,354,779
Foreign currency translation adjustments	(25,992)
Balance at end of period	1,328,787
Reportable Segments | Bromine Specialties
Goodwill [Roll Forward]
Balance at beginning of period	20,319
Foreign currency translation adjustments	0
Balance at end of period	20,319
Reportable Segments | Catalysts
Goodwill [Roll Forward]
Balance at beginning of period	185,485
Foreign currency translation adjustments	(6,936)
Balance at end of period	178,549
Reportable Segments | All Other
Goodwill [Roll Forward]
Balance at beginning of period	6,586
Foreign currency translation adjustments	0
Balance at end of period	$ 6,586