Fair Value Measurements and Financial Instruments - Schedule of Designated Derivative Activity (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Interest rate swaps | Fair Value Hedges | Designated as Hedging Instrument
Derivative [Line Items]
Notional value entered into	$ 0	$ 0	$ 0	$ 0
Notional value settled	985,000,000	0	985,000,000	0
Pre-tax gain recognized in Interest expense	0	1,000,000	0	3,000,000
Interest rate swaps | Cash Flow Hedging | Designated as Hedging Instrument
Derivative [Line Items]
Cash received (paid) for settlement of derivatives			(45,000,000)	0
Cross currency swaps
Derivative [Line Items]
Pre-tax gain recognized in Interest expense	0	0	0	0
Cross currency swaps | Fair Value Hedges | Designated as Hedging Instrument
Derivative [Line Items]
Notional value entered into	0	0	0	2,146,000,000
Notional value settled	817,000,000	552,000,000	1,176,000,000	3,619,000,000
Exchange gains (losses) from the conversion of foreign currency denominated as debt	2,422,000,000	(92,000,000)	3,500,000,000	(834,000,000)
Excluded component	(28,000,000)	(116,000,000)	(877,000,000)	166,000,000
Cash received (paid) for settlement of derivatives			(80,000,000)	(243,000,000)
Cross currency swaps | Fair Value Hedges | Designated as Hedging Instrument | Verizon Stated And Floating Rate Notes and Bonds
Derivative [Line Items]
Exchange gains (losses) from the conversion of foreign currency denominated as debt	(2,422,000,000)	92,000,000	(3,500,000,000)	834,000,000
Cross currency swaps | Fair Value Hedges | Designated as Hedging Instrument | Interest Expense
Derivative [Line Items]
Excluded component	23,000,000	24,000,000	46,000,000	50,000,000
Treasury rate locks | Cash Flow Hedging | Designated as Hedging Instrument
Derivative [Line Items]
Notional value entered into	4,900,000,000	0	4,900,000,000	0
Notional value settled	0	0	0	0
Pre-tax gain (loss) recognized in Other income (expense), net	$ (55,000,000)	$ 0	$ (55,000,000)	$ 0