Revenues and Contract Costs - Additional Information (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2023 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2023 USD ($) segment	Jun. 30, 2022 USD ($)
Disaggregation of Revenue [Line Items]
Number of reportable segments | segment			2
Revenue from arrangements not accounted for under Topic 606	$ 754,000,000	$ 775,000,000	$ 1,500,000,000	$ 1,600,000,000
Amortization of deferred contract costs	791,000,000	735,000,000	1,600,000,000	1,500,000,000
Contract assets impairment charge	$ 0	$ 0	$ 0	$ 0
Wireless postpaid contracts
Disaggregation of Revenue [Line Items]
Percentage of month-to-month contracts of total service contracts	94.00%	94.00%	94.00%	94.00%
Wireline Consumer And Business Markets And Other Contracts
Disaggregation of Revenue [Line Items]
Percentage of month-to-month contracts of total service contracts	94.00%	89.00%	94.00%	89.00%
Minimum
Disaggregation of Revenue [Line Items]
Deferred contract cost, amortization period	1 year		1 year
Minimum | Wireless Service, Option One
Disaggregation of Revenue [Line Items]
Customer contracts service term			1 month
Minimum | Wireless Service, Option Two
Disaggregation of Revenue [Line Items]
Customer contracts service term			1 month
Minimum | Consumer
Disaggregation of Revenue [Line Items]
Customer contracts service term			12 months
Minimum | Consumer | Reseller Arrangements
Disaggregation of Revenue [Line Items]
Customer contracts service term			2 years
Maximum
Disaggregation of Revenue [Line Items]
Deferred contract cost, amortization period	7 years		7 years
Maximum | Wireless Service, Option One
Disaggregation of Revenue [Line Items]
Customer contracts service term			36 months
Maximum | Wireless Service, Option Two
Disaggregation of Revenue [Line Items]
Customer contracts service term			24 months
Maximum | Consumer
Disaggregation of Revenue [Line Items]
Customer contracts service term			2 years
Maximum | Business
Disaggregation of Revenue [Line Items]
Customer contracts service term			12 months