Wireless Licenses, Goodwill and Other Intangible Assets - Changes in Carrying Amount of Goodwill (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Goodwill [Roll Forward]
Beginning balance	$ 28,603	$ 24,773
Acquisitions	100	3,852
Reclassifications, adjustments and other	(32)	(22)
Ending balance	28,671	28,603
Goodwill accumulated impairment			$ 4,800
Goodwill, impairment loss	16
Operating Segments | Consumer
Goodwill [Roll Forward]
Beginning balance	21,042	17,222
Acquisitions	100	3,818
Reclassifications, adjustments and other	0	2
Ending balance	21,142	21,042
Operating Segments | Business
Goodwill [Roll Forward]
Beginning balance	7,515	7,535
Acquisitions	0	0
Reclassifications, adjustments and other	(13)	(20)
Ending balance	7,502	7,515
Other
Goodwill [Roll Forward]
Beginning balance	46	16
Acquisitions	0	34
Reclassifications, adjustments and other	(19)	(4)
Ending balance	$ 27	$ 46