Property, Plant and Equipment - Schedule of Property, Plant, and Equipment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Property, plant and equipment
Gross property, plant and equipment	$ 53,267	$ 51,204
Accumulated depreciation	(26,859)	(24,352)
Net property, plant and equipment	26,408	26,852
Land
Property, plant and equipment
Gross property, plant and equipment	871	883
Fiber, conduit and other outside plant
Property, plant and equipment
Gross property, plant and equipment	$ 23,936	22,798
Fiber, conduit and other outside plant | Minimum
Property, plant and equipment
Depreciable Lives	15 years
Fiber, conduit and other outside plant | Maximum
Property, plant and equipment
Depreciable Lives	45 years
Central office and other network electronics
Property, plant and equipment
Gross property, plant and equipment	$ 18,736	18,538
Central office and other network electronics | Minimum
Property, plant and equipment
Depreciable Lives	3 years
Central office and other network electronics | Maximum
Property, plant and equipment
Depreciable Lives	10 years
Support assets
Property, plant and equipment
Gross property, plant and equipment	$ 8,020	7,586
Support assets | Minimum
Property, plant and equipment
Depreciable Lives	3 years
Support assets | Maximum
Property, plant and equipment
Depreciable Lives	30 years
Construction in progress
Property, plant and equipment
Gross property, plant and equipment	$ 1,704	$ 1,399