Long Term Debt - Schedule of carrying values and fair values of debt instruments (Details) - USD ($) $ in Millions		Mar. 31, 2024	Dec. 31, 2023
CNK [Member]
Debt Instrument [Line Items]
Fair value	[1]	$ 2,562.2	$ 2,460.3
CUSA [Member]
Debt Instrument [Line Items]
Fair value		$ 1,924.5	$ 1,903.8

[1] The fair value of the 4.50% convertible senior notes was $637.7 and $556.5 as of March 31, 2024 and December 31, 2023, respectively.