Goodwill and Other Intangibles - Changes in Goodwill (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2019 USD ($)
Goodwill [Roll Forward]
Balance at beginning of period	$ 1,567,169
Foreign currency translation adjustments	(705)
Balance at end of period	1,566,464
Reportable Segments | Lithium
Goodwill [Roll Forward]
Balance at beginning of period	1,354,779
Foreign currency translation adjustments	(626)
Balance at end of period	1,354,153
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	(79)
Balance at end of period	185,406
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