Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Earnings Per Share
Net income	$ 3,949	$ 4,816	$ 12,271	$ 14,823
Less: Net income attributable to noncontrolling interest	(249)	(98)	(762)	(311)
Net Income attributable to AT&T	3,700	4,718	11,509	14,512
Share-based payment	6	4	16	13
Numerator for diluted earnings per share	$ 3,706	$ 4,722	$ 11,525	$ 14,525
Weighted average number of common shares outstanding	7,327	7,284	7,321	6,603
Share-based payment (in shares)	29	36	29	27
Denominator for diluted earnings per share	7,356	7,320	7,350	6,630
Basic Earnings Per Share Attributable to AT&T	$ 0.50	$ 0.65	$ 1.57	$ 2.19
Diluted Earnings Per Share Attributable to AT&T	$ 0.50	$ 0.65	$ 1.57	$ 2.19