Device Payment Plan Agreement and Wireless Service Receivables - Schedule of Receivables (Details) - USD ($) $ in Millions	Mar. 31, 2025	Dec. 31, 2024
Financing Receivable, after Allowance for Credit Loss, Current [Abstract]
Accounts receivable, net	$ 14,902	$ 15,141
Accounts and Financing Receivable, after Allowance for Credit Loss, Current [Abstract]
Accounts receivable	27,033	27,261
Less Allowance for credit losses	1,144	1,152
Accounts receivable, net	25,889	$ 26,109
Device payment plan agreement
Financing Receivable, after Allowance for Credit Loss, Current [Abstract]
Accounts receivable	15,614
Less Allowance for credit losses	712
Accounts receivable, net	14,902
Wireless service
Accounts Receivable, after Allowance for Credit Loss, Current [Abstract]
Accounts receivable	5,935
Less Allowance for credit losses	245
Accounts receivable, net	5,690
Other receivables
Accounts Receivable, after Allowance for Credit Loss, Current [Abstract]
Accounts receivable	5,484
Less Allowance for credit losses	187
Accounts receivable, net	$ 5,297