v3.24.3
Sales Of Receivables (Equipment Installment and AT&T Revolving Programs) (Narrative) (Details) - USD ($)
$ in Millions
 9 Months Ended
Sep. 30, 2024
Dec. 31, 2023
Asset Pledged as Collateral without Right    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Receivables, Fair Value Disclosure $ 195  
Equipment Installment | Guarantee Obligation    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Guarantee obligation 236 $ 385
Equipment Installment | Accounts payable and accrued liabilities | Guarantee Obligation    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Guarantee obligation 121 111
Equipment Installment | Deferred Purchase Price Receivable    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Deferred purchase price receivable 2,875 2,270
Equipment Installment | Deferred Purchase Price Receivable | Prepaid and other current assets    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Deferred purchase price receivable 1,681 $ 1,296
Revolving Receivables Program    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Revolving agreement, transfer amount (up to) $ 2,770