Investments in unconsolidated entities - Components of other long-term investments (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Debt and Equity Securities, FV-NI [Line Items]
Other long-term investments	$ 456.1	$ 4.0
Equity method eligible entities
Debt and Equity Securities, FV-NI [Line Items]
Other long-term investments	258.1	0.0
Other unconsolidated investments
Debt and Equity Securities, FV-NI [Line Items]
Other long-term investments	$ 198.0	$ 4.0