Segment Reporting (Performance Measures) (Schedule) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Segment Reporting Information [Line Items]
Revenue	$ 1,868.4	$ 1,853.3
Adjusted EBITDA	624.5	684.3
VMO2 JV
Segment Reporting Information [Line Items]
Revenue	3,162.7
VMO2 JV | Equity Method Investment, Nonconsolidated Investee or Group of Investees
Segment Reporting Information [Line Items]
Adjusted EBITDA	1,025.9	1,395.3
VodafoneZiggo JV
Segment Reporting Information [Line Items]
Revenue	1,083.4	1,130.0
VodafoneZiggo JV | Equity Method Investment, Nonconsolidated Investee or Group of Investees
Segment Reporting Information [Line Items]
Adjusted EBITDA	471.5	537.8
Operating Segments | Switzerland
Segment Reporting Information [Line Items]
Revenue	807.4	821.4
Adjusted EBITDA	263.0	290.8
Operating Segments | Belgium
Segment Reporting Information [Line Items]
Revenue	754.5	724.4
Adjusted EBITDA	302.9	338.1
Operating Segments | Ireland
Segment Reporting Information [Line Items]
Revenue	123.0	127.8
Adjusted EBITDA	41.5	47.1
Central and Other
Segment Reporting Information [Line Items]
Revenue	244.5	241.4
Adjusted EBITDA	32.1	24.8
Intersegment eliminations
Segment Reporting Information [Line Items]
Revenue	(61.0)	(61.7)
Adjusted EBITDA	$ (15.0)	$ (16.5)