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Revenue - Schedule of Accounts Receivable (Details) - USD ($) $ in Millions | Sep. 30, 2025 | Dec. 31, 2024
--- | --- | ---
Disaggregation of Revenue [Line Items] |  |
Receivables, net | $ 13,214 | $ 13,661
Noncurrent receivables, net (included in other noncurrent assets, net) | 1,810 | 1,853
Equipment Installment Plan | Notes Receivable | Unbilled Revenues |  |
Disaggregation of Revenue [Line Items] |  |
Receivables, net | 1,955 | 1,827
Noncurrent receivables, net (included in other noncurrent assets, net) | 1,216 | 1,225
Total | $ 3,172 | $ 3,052

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