Other Assets and Liabilities - Other Non-Current Assets (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Schedule of Other Assets and Liabilities [Line Items]
Supply and Offtake receivable	$ 32.7	$ 32.7
Other Equity investment	10.4	8.9
Deferred financing costs	7.3	8.5
Other	18.1	17.7
Total	$ 68.5	$ 67.8