v3.19.3.a.u2
Consolidated Statements Of Changes In Stockholders' Equity (Parenthetical) - $ / shares
 1 Months Ended 3 Months Ended 12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2019
 [1]
Sep. 30, 2019
 [1]
Jun. 30, 2019
 [1]
Mar. 31, 2019
 [1]
Dec. 31, 2018
 [1]
Sep. 30, 2018
 [1]
Jun. 30, 2018
 [1]
Mar. 31, 2018
 [1]
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Consolidated Statements Of Changes In Stockholders' Equity                                
Net income attributable to AT&T, per diluted share     $ 0.33 $ 0.50 $ 0.51 $ 0.56 $ 0.66 $ 0.65 $ 0.81 $ 0.75 $ 0.65 $ 0.81 $ 0.75 $ 1.89 $ 2.85 $ 4.76
Dividends to stockholders, per share $ 0.52 $ 0.51                       $ 2.05 $ 2.01 $ 1.97
[1]
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.