Wireless Licenses, Goodwill and Other Intangible Assets - Composition of Other Intangible Assets, Net (Detail) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Finite-Lived Intangible Assets [Line Items]
Gross Amount	$ 31,421	$ 30,562
Accumulated Amortization	(20,324)	(19,101)
Net Amount	11,097	11,461
Customer Lists
Finite-Lived Intangible Assets [Line Items]
Gross Amount	4,335	4,335
Accumulated Amortization	(1,907)	(1,646)
Net Amount	$ 2,428	2,689
Customer Lists | Minimum
Finite-Lived Intangible Assets [Line Items]
Other intangible asset, useful life	5 years
Customer Lists | Maximum
Finite-Lived Intangible Assets [Line Items]
Other intangible asset, useful life	13 years
Non-Network Internal-Use Software
Finite-Lived Intangible Assets [Line Items]
Other intangible asset, useful life	7 years
Gross Amount	$ 24,247	23,421
Accumulated Amortization	(17,210)	(16,397)
Net Amount	7,037	7,024
Other
Finite-Lived Intangible Assets [Line Items]
Gross Amount	2,839	2,806
Accumulated Amortization	(1,207)	(1,058)
Net Amount	$ 1,632	$ 1,748
Other | Minimum
Finite-Lived Intangible Assets [Line Items]
Other intangible asset, useful life	4 years
Other | Maximum
Finite-Lived Intangible Assets [Line Items]
Other intangible asset, useful life	25 years