Revenue from Contracts with Customers - Schedule of Disaggregation of Revenue (Details) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2025 USD ($) customer_category	Sep. 30, 2024 USD ($)	Sep. 30, 2025 USD ($) customer_category	Sep. 30, 2024 USD ($)
Disaggregation of Revenue [Line Items]
Number of customer categories \| customer_category	3		3
Total revenues	$ 21,957	$ 20,162	$ 63,975	$ 59,528
Postpaid phone revenues
Disaggregation of Revenue [Line Items]
Total revenues	12,645	11,600	36,497	34,055
Postpaid other revenues
Disaggregation of Revenue [Line Items]
Total revenues	2,237	1,708	6,057	4,783
Total postpaid service revenues
Disaggregation of Revenue [Line Items]
Total revenues	$ 14,882	$ 13,308	$ 42,554	$ 38,838

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.

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+ Details

- Definition

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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