Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Earnings Per Share
Net income	$ 3,078	$ 3,187	$ 9,601	$ 10,654
Less: Net income attributable to noncontrolling interest	(84)	(57)	(262)	(213)
Net Income attributable to AT&T	2,994	3,130	9,339	10,441
Share-based payment	3	2	9	9
Numerator for diluted earnings per share	$ 2,997	$ 3,132	$ 9,348	$ 10,450
Weighted-average number of common shares outstanding	5,924	5,198	5,447	5,208
Share-based payment (in shares)	19	16	16	16
Denominator for diluted earnings per share	5,943	5,214	5,463	5,224
Basic Earnings Per Share Attributable to AT&T	$ 0.50	$ 0.60	$ 1.71	$ 2.00
Diluted Earnings Per Share Attributable to AT&T	$ 0.50	$ 0.60	$ 1.71	$ 2.00