Segment Reporting (Revenue by Major Category) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Segment Reporting Information [Line Items]
Revenue	$ 1,945.1	$ 1,868.4
Total residential fixed revenue
Segment Reporting Information [Line Items]
Revenue	744.5	739.1
Total subscription revenue
Segment Reporting Information [Line Items]
Revenue	730.8	724.8
Broadband internet
Segment Reporting Information [Line Items]
Revenue	382.3	359.5
Video
Segment Reporting Information [Line Items]
Revenue	264.3	273.2
Fixed-line telephony
Segment Reporting Information [Line Items]
Revenue	84.2	92.1
Non-subscription revenue
Segment Reporting Information [Line Items]
Revenue	13.7	14.3
Total residential revenue
Segment Reporting Information [Line Items]
Revenue	1,258.4	1,229.4
Total residential mobile revenue
Segment Reporting Information [Line Items]
Revenue	513.9	490.3
Subscription revenue
Segment Reporting Information [Line Items]
Revenue	376.6	356.4
Non-subscription revenue
Segment Reporting Information [Line Items]
Revenue	137.3	133.9
Total B2B revenue
Segment Reporting Information [Line Items]
Revenue	375.9	357.2
Subscription revenue
Segment Reporting Information [Line Items]
Revenue	144.9	133.4
Non-subscription revenue
Segment Reporting Information [Line Items]
Revenue	231.0	223.8
Other revenue
Segment Reporting Information [Line Items]
Revenue	$ 310.8	$ 281.8