Property, Plant and Equipment (Detail) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 331,406	$ 320,108
Less Accumulated depreciation	222,884	211,798
Property, plant and equipment, net	108,522	108,310
Land
Property, Plant and Equipment [Line Items]
Property, plant and equipment	740	751
Buildings and equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 39,130	36,940
Buildings and equipment | Minimum
Property, Plant and Equipment [Line Items]
Property, plant and equipment useful life	7 years
Buildings and equipment | Maximum
Property, Plant and Equipment [Line Items]
Property, plant and equipment useful life	45 years
Central office and other network equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 176,680	170,161
Central office and other network equipment | Minimum
Property, Plant and Equipment [Line Items]
Property, plant and equipment useful life	3 years
Central office and other network equipment | Maximum
Property, Plant and Equipment [Line Items]
Property, plant and equipment useful life	15 years
Antennas, cable, conduit, poles and towers
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 82,810	78,355
Antennas, cable, conduit, poles and towers | Minimum
Property, Plant and Equipment [Line Items]
Property, plant and equipment useful life	4 years
Antennas, cable, conduit, poles and towers | Maximum
Property, Plant and Equipment [Line Items]
Property, plant and equipment useful life	50 years
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 10,562	10,355
Leasehold improvements | Minimum
Property, Plant and Equipment [Line Items]
Property, plant and equipment useful life	5 years
Leasehold improvements | Maximum
Property, Plant and Equipment [Line Items]
Property, plant and equipment useful life	20 years
Work in progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 9,424	12,092
Furniture, vehicles and other
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 12,060	$ 11,454
Furniture, vehicles and other | Minimum
Property, Plant and Equipment [Line Items]
Property, plant and equipment useful life	3 years
Furniture, vehicles and other | Maximum
Property, Plant and Equipment [Line Items]
Property, plant and equipment useful life	20 years