Segment Reporting (Revenue by Major Category) (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
Total residential fixed revenue
Segment Reporting Information [Line Items]
Revenue	732.1	762.5
Total subscription revenue
Segment Reporting Information [Line Items]
Revenue	724.8	750.6
Broadband internet
Segment Reporting Information [Line Items]
Revenue	359.5	360.2
Video
Segment Reporting Information [Line Items]
Revenue	273.2	286.5
Fixed-line telephony
Segment Reporting Information [Line Items]
Revenue	92.1	103.9
Non-subscription revenue
Segment Reporting Information [Line Items]
Revenue	7.3	11.9
Total residential revenue
Segment Reporting Information [Line Items]
Revenue	1,222.4	1,261.0
Total residential mobile revenue
Segment Reporting Information [Line Items]
Revenue	490.3	498.5
Subscription revenue
Segment Reporting Information [Line Items]
Revenue	356.4	353.2
Non-subscription revenue
Segment Reporting Information [Line Items]
Revenue	133.9	145.3
Total B2B revenue
Segment Reporting Information [Line Items]
Revenue	357.2	354.3
Subscription revenue
Segment Reporting Information [Line Items]
Revenue	133.4	132.9
Non-subscription revenue
Segment Reporting Information [Line Items]
Revenue	223.8	221.4
Other revenue
Segment Reporting Information [Line Items]
Revenue	$ 288.8	$ 238.0