Long-lived Assets (Schedule of PP&E) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Property and equipment gross	$ 15,062.5	$ 15,460.8
Accumulated depreciation	(8,081.0)	(7,834.2)
Total property and equipment, net	6,981.5	7,626.6
Distribution systems
Property, Plant and Equipment [Line Items]
Property and equipment gross	9,472.8	9,646.4
Customer premises equipment
Property, Plant and Equipment [Line Items]
Property and equipment gross	1,279.2	1,447.7
Support equipment, buildings and land
Property, Plant and Equipment [Line Items]
Property and equipment gross	$ 4,310.5	$ 4,366.7
Minimum | Distribution systems
Property, Plant and Equipment [Line Items]
Estimated useful life at December 31, 2021	3 years
Minimum | Customer premises equipment
Property, Plant and Equipment [Line Items]
Estimated useful life at December 31, 2021	3 years
Minimum | Support equipment, buildings and land
Property, Plant and Equipment [Line Items]
Estimated useful life at December 31, 2021	3 years
Maximum | Distribution systems
Property, Plant and Equipment [Line Items]
Estimated useful life at December 31, 2021	30 years
Maximum | Customer premises equipment
Property, Plant and Equipment [Line Items]
Estimated useful life at December 31, 2021	7 years
Maximum | Support equipment, buildings and land
Property, Plant and Equipment [Line Items]
Estimated useful life at December 31, 2021	33 years