Long-lived Assets (Schedule of PP&E) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Property and equipment gross	$ 16,108.7	$ 14,539.6
Accumulated depreciation	(8,748.5)	(8,035.1)
Total property and equipment, net	7,360.2	6,504.5
Distribution systems
Property, Plant and Equipment [Line Items]
Property and equipment gross	10,638.0	9,134.3
Support equipment, buildings and land
Property, Plant and Equipment [Line Items]
Property and equipment gross	4,116.0	4,067.2
Customer premises equipment
Property, Plant and Equipment [Line Items]
Property and equipment gross	$ 1,354.7	$ 1,338.1
Minimum | Distribution systems
Property, Plant and Equipment [Line Items]
Estimated useful life at December 31, 2023	3 years
Minimum | Support equipment, buildings and land
Property, Plant and Equipment [Line Items]
Estimated useful life at December 31, 2023	3 years
Minimum | Customer premises equipment
Property, Plant and Equipment [Line Items]
Estimated useful life at December 31, 2023	4 years
Maximum | Distribution systems
Property, Plant and Equipment [Line Items]
Estimated useful life at December 31, 2023	30 years
Maximum | Support equipment, buildings and land
Property, Plant and Equipment [Line Items]
Estimated useful life at December 31, 2023	33 years
Maximum | Customer premises equipment
Property, Plant and Equipment [Line Items]
Estimated useful life at December 31, 2023	7 years