Property, Plant and Equipment - Net Property, Plant and Equipment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment, Net [Abstract]
Gross property, plant and equipment	$ 15,059	$ 16,656
Accumulated depreciation	(6,879)	(8,347)
Net property, plant and equipment	8,180	8,309
Land
Property, Plant and Equipment, Net [Abstract]
Gross property, plant and equipment	335	332
Fiber, conduit and other outside plant
Property, Plant and Equipment, Net [Abstract]
Gross property, plant and equipment	$ 6,406	8,270
Fiber, conduit and other outside plant | Minimum
Property, Plant and Equipment [Line Items]
Depreciable lives	15 years
Fiber, conduit and other outside plant | Maximum
Property, Plant and Equipment [Line Items]
Depreciable lives	45 years
Central office and other network electronics
Property, Plant and Equipment, Net [Abstract]
Gross property, plant and equipment	$ 5,106	4,964
Central office and other network electronics | Minimum
Property, Plant and Equipment [Line Items]
Depreciable lives	7 years
Central office and other network electronics | Maximum
Property, Plant and Equipment [Line Items]
Depreciable lives	10 years
Support assets
Property, Plant and Equipment, Net [Abstract]
Gross property, plant and equipment	$ 2,721	2,679
Support assets | Minimum
Property, Plant and Equipment [Line Items]
Depreciable lives	3 years
Support assets | Maximum
Property, Plant and Equipment [Line Items]
Depreciable lives	30 years
Construction in progress
Property, Plant and Equipment, Net [Abstract]
Gross property, plant and equipment	$ 491	$ 411