v3.20.2
Additional Financial Information (Narrative) (Details)
€ in Millions, $ in Millions
1 Months Ended 3 Months Ended 6 Months Ended
May 31, 2020
USD ($)
Jun. 30, 2020
EUR (€)
Jun. 30, 2020
USD ($)
Jun. 30, 2020
USD ($)
Jun. 30, 2019
USD ($)
Apr. 01, 2020
USD ($)
Additional Financial Information [Line Items]            
Long-Term Debt Obligation     $ 168,964 $ 168,964    
Repayment of long-term debt       17,284 $ 16,124  
Notes And Debentures [Member]            
Additional Financial Information [Line Items]            
Commercial paper     $ 2,960 $ 2,960    
Notes And Debentures [Member] | Long-Term Debt Issuance [Member]            
Additional Financial Information [Line Items]            
Weighted Average Interest Rate     3.50% 3.50%    
Notes And Debentures [Member] | Long-Term Debt Redemptions [Member]            
Additional Financial Information [Line Items]            
Weighted Average Interest Rate     3.40% 3.40%    
Term Credit Agreements [Member]            
Additional Financial Information [Line Items]            
Repayment of long-term debt     $ 1,800      
Term Credit Agreements [Member] | Bank of America, N.A. [Member]            
Additional Financial Information [Line Items]            
Short-Term Borrowings           $ 5,500
Repayment of Short Term $ 5,500          
AT&T Global Notes Due 2027 To 2060 [Member]            
Additional Financial Information [Line Items]            
Proceeds from Issuance of Debt     16,545      
AT&T Global Notes Due 2028 To 2038 [Member]            
Additional Financial Information [Line Items]            
Proceeds from Issuance of Debt   € 3,000 3,281      
AT&T Global Notes Due 2020 To 2047 [Member]            
Additional Financial Information [Line Items]            
Repayment of long-term debt     12,689      
Other Debt [Member]            
Additional Financial Information [Line Items]            
Repayment of long-term debt     $ 1,000      
Vendor Financing Program [Member]            
Additional Financial Information [Line Items]            
Noncash Investing Activities       $ 1,680 $ 1,265