Debt - Credit Facilities, Non-Cash Transaction, Guarantees (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024
Debt Instrument [Line Items]
Facility Capacity	$ 22,000,000,000
Unused Capacity	11,964,000,000
Principal Amount Outstanding	5,118,000,000
Debt extinguishment gains (losses)	90,000,000	$ 110,000,000
Guarantee of Debentures of Operating Telephone Company Subsidiaries
Debt Instrument [Line Items]
Principal amount outstanding in connection with the guarantee of debt obligations	614,000,000
Network Equipment | Alternative Financing Facility
Debt Instrument [Line Items]
Value of purchase assets financed	627,000,000	463,000,000
Long-term debt maturing within one year	2,600,000,000		$ 2,500,000,000
Verizon revolving credit facility
Debt Instrument [Line Items]
Facility Capacity	12,000,000,000
Unused Capacity	11,964,000,000
Principal Amount Outstanding	0
Amount drawn from credit facilities	0
Various export credit facilities
Debt Instrument [Line Items]
Facility Capacity	10,000,000,000
Unused Capacity	0
Principal Amount Outstanding	5,118,000,000
Amount drawn from credit facilities	$ 0	$ 0