Balance Sheet Accounts - Schedule of Other Current Assets (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Deferred costs recoverable from the U.S. government	$ 40.4	$ 37.4
Income tax receivable	0.0	13.8
Inventories	11.1	10.0
Prepaid expenses	15.5	15.3
Other	26.6	23.0
Other current assets	$ 93.6	$ 99.5

Amount of asset related to consideration paid in advance for costs that provide economic benefits within a future period of one year or the normal operating cycle, if longer.

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