Property, Plant and Equipment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Property, Plant and Equipment [Line Items]
Gross property, plant and equipment	$ 16,939	$ 15,890
Accumulated depreciation	(8,239)	(7,617)
Net property, plant and equipment	8,700	8,273
Depreciation expense	756	781	$ 833
Land
Property, Plant and Equipment [Line Items]
Gross property, plant and equipment	334	339
Fiber, conduit and other outside plant
Property, Plant and Equipment [Line Items]
Gross property, plant and equipment	$ 7,126	6,755
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 [Line Items]
Gross property, plant and equipment	$ 5,488	5,283
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 [Line Items]
Gross property, plant and equipment	$ 2,845	2,766
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 [Line Items]
Gross property, plant and equipment	$ 1,146	$ 747