| Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] |
| Three months ended | | Six months ended | | June 30, | | June 30, | | 2020 | | 2019 | | 2020 | | 2019 | Numerators | | | | | | | | | | | | Numerator for basic earnings per share: | | | | | | | | | | | | Net Income | $ | 1,563 | | $ | 3,974 | | $ | 6,526 | | $ | 8,322 | Less: Net income attributable to noncontrolling interest | | (282) | | | (261) | | | (635) | | | (513) | Net Income attributable to AT&T | | 1,281 | | | 3,713 | | | 5,891 | | | 7,809 | Less: Preferred stock dividends | | (52) | | | - | | | (84) | | | - | Net income attributable to common stock | | 1,229 | | | 3,713 | | | 5,807 | | | 7,809 | Dilutive potential common shares: | | | | | | | | | | | | Share-based payment | | 5 | | | 4 | | | 11 | | | 10 | Numerator for diluted earnings per share | $ | 1,234 | | $ | 3,717 | | $ | 5,818 | | $ | 7,819 | Denominators (000,000) | | | | | | | | | | | | Denominator for basic earnings per share: | | | | | | | | | | | | Weighted average number of common shares outstanding | | 7,145 | | | 7,323 | | | 7,166 | | | 7,318 | Dilutive potential common shares: | | | | | | | | | | | | Share-based payment (in shares) | | 25 | | | 30 | | | 26 | | | 29 | Denominator for diluted earnings per share | | 7,170 | | | 7,353 | | | 7,192 | | | 7,347 | Basic earnings per share attributable to Common Stock | $ | 0.17 | | $ | 0.51 | | $ | 0.81 | | $ | 1.06 | Diluted earnings per share attributable to Common Stock | $ | 0.17 | | $ | 0.51 | | $ | 0.81 | | $ | 1.06 |
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