v3.19.3.a.u2
Valuation And Qualifying Accounts (Allowance For Doubtful Accounts) (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Allowance for Doubtful Accounts [Member]      
Valuation and Qualifying Accounts Disclosure [Line Items]      
Balance at Beginning of Period $ 907 $ 663 $ 661
Charged to Costs and Expenses [1] 2,575 1,791 1,642
Charged to Other Accounts [2] 0 0 0
Acquisitions [3] 0 179 0
Deductions [4] 2,247 1,726 1,640
Balance at End of Period 1,235 907 663
Allowance of Deferred Tax Assets [Member]      
Valuation and Qualifying Accounts Disclosure [Line Items]      
Balance at Beginning of Period 4,588 4,640 2,283
Charged to Costs and Expenses (18) (210) 2,376
Charged to Other Accounts [5] 371 (53) (19)
Acquisitions [3] 0 211 0
Deductions [6] 0 0 0
Balance at End of Period $ 4,941 $ 4,588 $ 4,640
[1]
(a) Includes amounts previously written off which were credited directly to this account when recovered. Excludes direct charges and credits to expense for nontrade receivables in the consolidated statements of income.
[2] (b) Includes amounts related to long-distance carrier receivables which were billed by AT&T.
[3] (c) Acqusition of Time Warner in 2018.
[4] (d) Amounts written off as uncollectible, or related to divested entities.
[5] (a) Includes current year reclassifications from other balance sheet accounts.
[6] (c) Reductions to valuation allowances related to deferred tax assets.