Segment Reporting (Balance Sheet Data of Reportable Segments) (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Segment Reporting Information [Line Items]
Long-lived assets	$ 18,166.0	$ 18,850.5
Total assets	42,895.0	46,917.0
VMO2 JV
Segment Reporting Information [Line Items]
Long-lived assets	41,087.5	51,689.8
Total assets	49,809.3	60,431.6
VodafoneZiggo JV
Segment Reporting Information [Line Items]
Long-lived assets	17,845.3	19,651.2
Total assets	20,211.9	21,288.5
Operating Segments | Switzerland
Segment Reporting Information [Line Items]
Long-lived assets	10,913.0	11,533.8
Total assets	13,095.6	13,812.9
Operating Segments | Belgium
Segment Reporting Information [Line Items]
Long-lived assets	5,736.5	5,652.3
Total assets	8,875.0	6,885.7
Operating Segments | Ireland
Segment Reporting Information [Line Items]
Long-lived assets	799.1	775.3
Total assets	1,070.8	894.8
Central and Other
Segment Reporting Information [Line Items]
Long-lived assets	717.4	889.1
Total assets	19,853.6	25,323.6
Total - continuing operations
Segment Reporting Information [Line Items]
Long-lived assets	18,166.0	18,850.5
Total assets	$ 42,895.0	$ 46,917.0