Segment Reporting (Performance Measures) (Schedule) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Segment Reporting Information [Line Items]
Total consolidated revenue	$ 1,269.1	$ 1,057.9	$ 2,440.3	$ 2,149.2
Total reportable segment revenue	5,420.6	5,342.1	10,474.4	10,624.5
VMO2 JV And VodafoneZiggo JV
Segment Reporting Information [Line Items]
Total consolidated revenue	(4,496.8)	(4,467.0)	(8,675.1)	(8,863.8)
VMO2 JV
Segment Reporting Information [Line Items]
Total consolidated revenue	3,373.5	3,375.4	6,499.8	6,658.2
VodafoneZiggo JV
Segment Reporting Information [Line Items]
Total consolidated revenue	1,123.3	1,091.6	2,175.3	2,205.6
Telenet
Segment Reporting Information [Line Items]
Total consolidated revenue	801.0	755.1	1,560.7	1,517.7
VM Ireland
Segment Reporting Information [Line Items]
Total consolidated revenue	122.8	120.0	238.6	243.0
Reportable Segment
Segment Reporting Information [Line Items]
Total consolidated revenue	38.0	71.9	73.4	135.1
Operating Segments
Segment Reporting Information [Line Items]
Total reportable segment revenue	5,420.5	5,341.1	10,474.3	10,622.6
Operating Segments \| VMO2 JV
Segment Reporting Information [Line Items]
Total consolidated revenue	3,373.5	3,375.4	6,499.8	6,658.2
Operating Segments \| VodafoneZiggo JV
Segment Reporting Information [Line Items]
Total consolidated revenue	1,123.3	1,091.6	2,175.3	2,205.6
Operating Segments \| Telenet
Segment Reporting Information [Line Items]
Total consolidated revenue	800.9	755.1	1,560.6	1,517.7
Operating Segments \| VM Ireland
Segment Reporting Information [Line Items]
Total consolidated revenue	122.8	119.0	238.6	241.1
Intersegment
Segment Reporting Information [Line Items]
Total reportable segment revenue	0.1	1.0	0.1	1.9
Intersegment \| Telenet
Segment Reporting Information [Line Items]
Total consolidated revenue	0.1	0.0	0.1	0.0
Intersegment \| VM Ireland
Segment Reporting Information [Line Items]
Total consolidated revenue	0.0	1.0	0.0	1.9
All other category
Segment Reporting Information [Line Items]
Total consolidated revenue	383.4	255.6	714.5	525.4
All other category \| Related Party
Segment Reporting Information [Line Items]
Total consolidated revenue	201.7	32.9	362.8	65.1
All other category \| JV Reportable Segments
Segment Reporting Information [Line Items]
Total consolidated revenue	143.7	150.8	278.3	325.2
Segments
Segment Reporting Information [Line Items]
Total consolidated revenue	$ (38.1)	$ (72.8)	$ (73.5)	$ (136.9)