Revenue Recognition - Revenue By Major Product Category (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020		Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Revenue	$ 122.9	$ 103.6	$ 102.2	$ 91.7	$ 82.2	$ 72.6	$ 64.9	$ 68.5	$ 420.4	$ 288.2	[1]	$ 388.4
Lithium Hydroxide
Disaggregation of Revenue [Line Items]
Revenue									208.0	157.5		213.8
Butyllithium
Disaggregation of Revenue [Line Items]
Revenue									105.4	87.1		99.9
High Purity Lithium Metal and Other Specialty Compounds
Disaggregation of Revenue [Line Items]
Revenue									36.9	31.7		52.4
Lithium Carbonate and Lithium Chloride
Disaggregation of Revenue [Line Items]
Revenue									$ 70.1	$ 11.9		$ 22.3

[1] As adjusted for the adoption of ASU 2020-06 using the full retrospective method.