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+ Details

Device Payment Plan Agreement and Wireless Service Receivables - Balance and Aging of Receivables (Detail) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Accounts, Notes, Loans and Financing Receivable [Line Items]
Device payment plan agreement receivables, gross	$ 34,004	$ 31,308
Device payment plan agreement
Accounts, Notes, Loans and Financing Receivable [Line Items]
Device payment plan agreement receivables, gross	32,951
Unbilled \| Financial Asset, Not Past Due \| Device payment plan agreement
Accounts, Notes, Loans and Financing Receivable [Line Items]
Device payment plan agreement receivables, gross	31,392
Billed \| Financial Asset, Not Past Due \| Device payment plan agreement
Accounts, Notes, Loans and Financing Receivable [Line Items]
Device payment plan agreement receivables, gross	1,201
Billed \| Financial Asset, Past Due \| Device payment plan agreement
Accounts, Notes, Loans and Financing Receivable [Line Items]
Device payment plan agreement receivables, gross	$ 358