Property, Plant and Equipment, Net - Components (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment, Net
Total property, plant and equipment	$ 2,202.2	$ 2,033.4
Less accumulated depreciation	(1,476.4)	(1,311.1)
Plant, Property and Equipment, Net	725.8	722.3
Funding received, recorded as reduction to construction in progress	0.0	1.2
Depreciation expense	178.9	168.9	$ 150.1
Gain on sale of operating assets, net	1.1	0.0	$ 0.0
Distribution facilities
Property, Plant and Equipment, Net
Total property, plant and equipment	1,341.1	1,238.3
Customer premise equipment
Property, Plant and Equipment, Net
Total property, plant and equipment	272.3	267.7
Head-end equipment
Property, Plant and Equipment, Net
Total property, plant and equipment	256.7	228.5
Computer equipment and software
Property, Plant and Equipment, Net
Total property, plant and equipment	156.4	132.5
Telephony infrastructure
Property, Plant and Equipment, Net
Total property, plant and equipment	52.4	52.4
Buildings and leasehold improvements
Property, Plant and Equipment, Net
Total property, plant and equipment	33.4	32.1
Vehicles
Property, Plant and Equipment, Net
Total property, plant and equipment	22.9	23.7
Office and technical equipment
Property, Plant and Equipment, Net
Total property, plant and equipment	19.1	18.9
Land
Property, Plant and Equipment, Net
Total property, plant and equipment	4.4	4.4
Construction in progress (including material inventory and other)
Property, Plant and Equipment, Net
Total property, plant and equipment	$ 43.5	$ 34.9