Sales Of Receivables (Equipment Installment and AT&T Revolving Programs) (Narrative) (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2025	Dec. 31, 2024
Asset Pledged as Collateral without Right
Accounts, Notes, Loans and Financing Receivable [Line Items]
Receivables, Fair Value Disclosure	$ 234
Equipment Installment \| Guarantee Obligation
Accounts, Notes, Loans and Financing Receivable [Line Items]
Guarantee obligation	263	$ 301
Equipment Installment \| Accounts payable and accrued liabilities \| Guarantee Obligation
Accounts, Notes, Loans and Financing Receivable [Line Items]
Guarantee obligation	140	150
Equipment Installment \| Deferred Purchase Price Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Deferred purchase price receivable	1,990	3,185
Equipment Installment \| Deferred Purchase Price Receivable \| Prepaid and other current assets
Accounts, Notes, Loans and Financing Receivable [Line Items]
Deferred purchase price receivable	1,214	$ 1,906
Revolving Receivables Program \| Maximum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Revolving agreement, transfer amount (up to)	$ 2,940

AT&T INC. 10-Q