Wireless Licenses, Goodwill and Other Intangible Assets - Estimated Future Amortization Expense (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization expense for other intangible assets	$ 754	$ 706	$ 1,488	$ 1,404
Remainder of 2025	1,475		1,475
2026	2,738		2,738
2027	2,189		2,189
2028	1,683		1,683
2029	1,017		1,017
2030	$ 761		$ 761