Document And Entity Information In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Oct. 31, 2012
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Fiscal Year Focus	2012
Document Fiscal Period Focus	Q3
Document Period End Date	Sep. 30, 2012
Current Fiscal Year End Date	--12-31
Entity Central Index Key	0000732717
Entity Filer Category	Large Accelerated Filer
Entity Registrant Name	AT&T Inc.
Entity Common Stock, Shares Outstanding		5,680