Debt - Narrative (Detail)	1 Months Ended					12 Months Ended
	Jan. 31, 2024 USD ($) note	Dec. 31, 2023 USD ($)	Apr. 30, 2023 USD ($)	Mar. 31, 2023 USD ($)	Dec. 31, 2021 agreement	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Debt Instrument [Line Items]
Proceeds from issuance of long-term debt						$ 8,600,000,000	$ 17,800,000,000
Repayments of debt and capital lease obligations						10,600,000,000	13,600,000,000
Repayments of debt						2,022,000,000
Facility Capacity		$ 20,500,000,000				20,500,000,000
Principal Amount Outstanding		6,618,000,000				6,618,000,000
Value of purchase assets financed						3,800,000,000	6,000,000,000
Less long-term debt maturing within one year		12,973,000,000				12,973,000,000	9,813,000,000
Gain (loss) on debt extinguishment						308,000,000	(1,100,000,000)	$ (3,600,000,000)
Subsequent event
Debt Instrument [Line Items]
Debt instrument, number of notes | note	2
Alternative Financing Facility | Network Equipment
Debt Instrument [Line Items]
Value of purchase assets financed						1,300,000,000	832,000,000	$ 461,000,000
Less long-term debt maturing within one year		2,200,000,000				2,200,000,000	1,700,000,000
Line of Credit
Debt Instrument [Line Items]
Amount drawn from credit facilities				$ 500,000,000
Facility Capacity				500,000,000
Principal Amount Outstanding		0				0
Asset-Backed Debt
Debt Instrument [Line Items]
Proceeds from issuance of long-term debt						6,600,000,000	10,700,000,000
Repayments of debt						4,400,000,000	4,900,000,000
Secured debt, carrying value		22,200,000,000				22,200,000,000
Green Bond
Debt Instrument [Line Items]
Proceeds from issuance of long-term debt						1,000,000,000	1,000,000,000
Commercial Paper
Debt Instrument [Line Items]
Proceeds from commercial paper						15,900,000,000
Repayments of short-term debt						16,100,000,000
Commercial paper, amount outstanding		0				0
Asset Backed Notes
Debt Instrument [Line Items]
Principal Amount Issued		4,419,000,000				4,419,000,000
Asset Backed Notes | Subsequent event
Debt Instrument [Line Items]
Repayments of debt	$ 408,000,000
Principal Amount Issued	$ 1,900,000,000
Asset Backed Notes | Subsequent event | Minimum
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage	4.867%
Asset Backed Notes | Subsequent event | Maximum
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage	5.028%
Asset Backed Notes | Senior asset-backed notes
Debt Instrument [Line Items]
Repayments of debt						$ 3,700,000,000	$ 4,300,000,000
Asset Backed Notes | Term One | Senior asset-backed notes
Debt Instrument [Line Items]
Debt revolving period						18 months
Asset Backed Notes | Term Two | Senior asset-backed notes
Debt Instrument [Line Items]
Debt revolving period						2 years
Asset Backed Notes | Term Three | Senior asset-backed notes
Debt Instrument [Line Items]
Debt revolving period						3 years
Asset Backed Notes | Term Four | Senior asset-backed notes
Debt Instrument [Line Items]
Debt revolving period						5 years
2021 ABS Financing Facility
Debt Instrument [Line Items]
Repayments of debt			$ 700,000,000
Amount drawn from credit facilities		$ 925,000,000		325,000,000
Debt revolving period		18 months
Number of loan agreements | agreement					2
Outstanding balance		$ 8,500,000,000				$ 8,500,000,000
2021 ABS Financing Facility | Subsequent event
Debt Instrument [Line Items]
Repayments of debt	$ 900,000,000
2022 ABS Financing Facility | Senior asset-backed notes
Debt Instrument [Line Items]
Amount drawn from credit facilities		$ 450,000,000		$ 500,000,000
Debt revolving period		1 year
Outstanding balance		$ 3,000,000,000				3,000,000,000
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				$ 614,000,000