Device Payment Plan Agreement and Wireless Service Receivables - Schedule of Receivables (Details) - USD ($) $ in Millions	Jun. 30, 2025	Dec. 31, 2024
Financing Receivable, after Allowance for Credit Loss, Current [Abstract]
Accounts receivable, net	$ 14,932	$ 15,141
Accounts and Financing Receivable, after Allowance for Credit Loss, Current [Abstract]
Accounts receivable	27,440	27,261
Less Allowance for credit losses	1,165	1,152
Accounts receivable, net	26,275	$ 26,109
Device payment plan agreement
Financing Receivable, after Allowance for Credit Loss, Current [Abstract]
Accounts receivable	15,675
Less Allowance for credit losses	743
Accounts receivable, net	14,932
Wireless service
Accounts Receivable, after Allowance for Credit Loss, Current [Abstract]
Accounts receivable	6,357
Less Allowance for credit losses	240
Accounts receivable, net	6,117
Other receivables
Accounts Receivable, after Allowance for Credit Loss, Current [Abstract]
Accounts receivable	5,408
Less Allowance for credit losses	182
Accounts receivable, net	$ 5,226