Investments (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Schedule of Investments [Line Items]
Revenue	$ 1,945.1	$ 1,868.4
Other assets, current	692.9		$ 847.0
Proceeds from sale of debt securities	1,100.0	2,400.0
Realized net losses	11.2	19.2
UK JV Services
Schedule of Investments [Line Items]
Revenue	112.3	65.8
VMO2 JV
Schedule of Investments [Line Items]
Revenue	3,282.8	3,162.7
Dividends received		198.3
VMO2 JV | Related Party
Schedule of Investments [Line Items]
Other assets, current	29.4		18.6
JV Services
Schedule of Investments [Line Items]
Revenue	62.1	65.0
VodafoneZiggo JV
Schedule of Investments [Line Items]
Revenue	1,114.0	$ 1,083.4
VodafoneZiggo JV | Related Party
Schedule of Investments [Line Items]
Other assets, current	$ 37.6		$ 24.2