Segment Reporting (Capital Expenditures of Reportable Segments) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Segment Reporting Information [Line Items]
Total consolidated property and equipment additions	$ 285.6	$ 221.0
Assets acquired under capital-related vendor financing arrangements	(20.6)	(30.6)
Assets acquired under finance leases	0.0	(0.5)
Changes in current liabilities related to capital expenditures	(21.7)	16.2
Total capital expenditures, net	243.3	206.1
VMO2 JV And VodafoneZiggo JV
Segment Reporting Information [Line Items]
Total consolidated property and equipment additions	801.1	930.5
Operating Segments | Reportable Segment
Segment Reporting Information [Line Items]
Total consolidated property and equipment additions	1,090.7	1,153.6
Operating Segments | Telenet
Segment Reporting Information [Line Items]
Total consolidated property and equipment additions	246.7	183.7
Operating Segments | VM Ireland
Segment Reporting Information [Line Items]
Total consolidated property and equipment additions	42.9	39.4
Operating Segments | VMO2 JV
Segment Reporting Information [Line Items]
Total consolidated property and equipment additions	594.2	685.8
Operating Segments | VodafoneZiggo JV
Segment Reporting Information [Line Items]
Total consolidated property and equipment additions	206.9	244.7
Central and Other
Segment Reporting Information [Line Items]
Total consolidated property and equipment additions	6.0	7.4
Intersegment Eliminations
Segment Reporting Information [Line Items]
Total consolidated property and equipment additions	$ (10.0)	$ (9.5)