Revenue from Contracts with Customers - Schedule of Disaggregation of Revenue (Details) $ in Millions	3 Months Ended
Mar. 31, 2025 USD ($) customer_category	Mar. 31, 2024 USD ($)
Disaggregation of Revenue [Line Items]
Number of customer categories \| customer_category	3
Revenues	$ 20,886	$ 19,594
Postpaid phone revenues
Disaggregation of Revenue [Line Items]
Revenues	11,733	11,145
Postpaid other revenues
Disaggregation of Revenue [Line Items]
Revenues	1,861	1,486
Total postpaid service revenues
Disaggregation of Revenue [Line Items]
Revenues	$ 13,594	$ 12,631

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

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+ Details