Wireless Licenses, Goodwill and Other Intangible Assets - Changes in Carrying Value of Goodwill (Detail) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2023
Goodwill [Roll Forward]
Beginning balance		$ 28,671
Reclassifications, adjustments and other		(24)
Ending balance	$ 28,647	28,647
Goodwill, impairment charge	27	27
Operating Segments | Consumer
Goodwill [Roll Forward]
Beginning balance		21,142
Reclassifications, adjustments and other		0
Ending balance	21,142	21,142
Operating Segments | Business
Goodwill [Roll Forward]
Beginning balance		7,502
Reclassifications, adjustments and other		3
Ending balance	7,505	7,505
Other
Goodwill [Roll Forward]
Beginning balance		27
Reclassifications, adjustments and other		(27)
Ending balance	$ 0	$ 0