Revenue and Contracts with Customers (Revenue from External Customers by Geographic Areas) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Revenue	$ 91.3	$ 33.6	$ 209.3	$ 154.3
Product [Member]
Revenue	32.0	18.7	115.3	112.8
Product [Member] | United States
Revenue	13.8	18.7	68.6	66.7
Product [Member] | Other Foreign
Revenue	$ 18.2	$ 0.0	$ 46.7	$ 46.1