v3.19.3.a.u2
Quarterly Financial Information (Unaudited) (Quarterly Financial Results) (Details) - USD ($)
$ / shares in Units, $ in Millions
 3 Months Ended 12 Months Ended
Dec. 31, 2019
Sep. 30, 2019
Jun. 30, 2019
Mar. 31, 2019
Dec. 31, 2018
Sep. 30, 2018
Jun. 30, 2018
Mar. 31, 2018
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Quarterly Financial Information (Unaudited)                            
Total operating revenues $ 46,821 [1],[2] $ 44,588 [1] $ 44,957 [1] $ 44,827 [1] $ 47,993 [1] $ 45,739 [1] $ 38,986 [1] $ 38,038 [1] $ 45,739 $ 38,986 $ 38,038 $ 181,193 $ 170,756 $ 160,546
Operating Income 5,321 [1],[2] 7,901 [1] 7,500 [1] 7,233 [1] 6,160 [1] 7,269 [1] 6,466 [1] 6,201 [1] 7,269 6,466 6,201 27,955 26,096 19,970
Net Income 2,704 [1],[2] 3,949 [1] 3,974 [1] 4,348 [1] 5,130 [1] 4,816 [1] 5,248 [1] 4,759 [1] 4,816 5,248 4,759 14,975 19,953 29,847
Net Income attributable to AT&T $ 2,394 [1],[2] $ 3,700 [1] $ 3,713 [1] $ 4,096 [1] $ 4,858 [1] $ 4,718 [1] $ 5,132 [1] $ 4,662 [1] $ 4,718 $ 5,132 $ 4,662 $ 13,903 $ 19,370 $ 29,450
Basic Earnings Per Share Attributable to Common Stock $ 0.33 [3] $ 0.50 [3] $ 0.51 [3] $ 0.56 [3] $ 0.66 [3] $ 0.65 [3] $ 0.81 [3] $ 0.75 [3] $ 0.65 $ 0.81 $ 0.75 $ 1.90 $ 2.85 $ 4.77
Diluted Earnings Per Share Attributable to Common Stock 0.33 [3] 0.50 [3] 0.51 [3] 0.56 [3] 0.66 [3] 0.65 [3] 0.81 [3] 0.75 [3] $ 0.65 $ 0.81 $ 0.75 1.89 2.85 $ 4.76
Sale of Stock Price Per Share [Line Items]                            
Stock Price Per Share 39.08 37.84 33.51 31.36 28.54 33.58 32.11 35.65       39.08 28.54  
High                            
Sale of Stock Price Per Share [Line Items]                            
Stock Price Per Share 39.70 38.75 33.55 31.64 34.30 34.28 36.39 39.29       39.70 34.30  
Low                            
Sale of Stock Price Per Share [Line Items]                            
Stock Price Per Share $ 36.40 $ 31.52 $ 30.05 $ 28.30 $ 26.80 $ 30.13 $ 31.17 $ 34.44       $ 36.40 $ 26.80  
[1] Includes actuarial gains and losses on pension and postretirement benefit plans (Note 15).
[2] Includes an asset abandonment charge (Note 7).
[3]
Quarterly earnings per share impacts may not add to full-year earnings per share impacts due to the difference in weighted-average common shares for the quarters versus the weighted-average common shares for the year.