Operating Financial Information for Reportable Segments (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Segment Reporting Information [Line Items]
Operating Revenues	$ 29,786	$ 28,552	$ 59,206	$ 56,794
Operating income	6,555	5,651	12,777	10,846
Wireless
Segment Reporting Information [Line Items]
Operating Revenues	19,976	18,577	39,499	36,850
Operating income	6,464	5,713	12,882	10,930
Wireline
Segment Reporting Information [Line Items]
Operating Revenues	9,734	9,931	19,564	19,876
Operating income	74	188	87	345
Total Segments
Segment Reporting Information [Line Items]
Operating Revenues	29,710	28,508	59,063	56,726
Operating income	6,538	5,901	12,969	11,275
Corporate, Eliminations and Other
Segment Reporting Information [Line Items]
Operating Revenues	76	44	143	68
Operating income	(220)	(250)	(429)	(429)
Reconciling Items
Segment Reporting Information [Line Items]
Operating income	17	(250)	(192)	(429)
External Operating Revenues
Segment Reporting Information [Line Items]
Operating Revenues	29,786	28,552	59,206	56,794
External Operating Revenues | Wireless
Segment Reporting Information [Line Items]
Operating Revenues	19,952	18,555	39,448	36,805
External Operating Revenues | Wireless | Service Revenue Retail Service
Segment Reporting Information [Line Items]
Operating Revenues	16,408	15,215	32,563	30,087
External Operating Revenues | Wireless | Service Revenue Other Service
Segment Reporting Information [Line Items]
Operating Revenues	656	544	1,213	1,068
External Operating Revenues | Wireless | Service Revenue
Segment Reporting Information [Line Items]
Operating Revenues	17,064	15,759	33,776	31,155
External Operating Revenues | Wireless | Equipment
Segment Reporting Information [Line Items]
Operating Revenues	1,949	1,766	3,758	3,601
External Operating Revenues | Wireless | Other
Segment Reporting Information [Line Items]
Operating Revenues	939	1,030	1,914	2,049
External Operating Revenues | Wireline
Segment Reporting Information [Line Items]
Operating Revenues	9,469	9,654	19,028	19,320
External Operating Revenues | Wireline | Mass Markets Consumer Retail
Segment Reporting Information [Line Items]
Operating Revenues	3,642	3,478	7,232	6,919
External Operating Revenues | Wireline | Mass Markets Small Business
Segment Reporting Information [Line Items]
Operating Revenues	647	664	1,295	1,323
External Operating Revenues | Wireline | Mass Markets
Segment Reporting Information [Line Items]
Operating Revenues	4,289	4,142	8,527	8,242
External Operating Revenues | Wireline | Global Enterprise Strategic Services
Segment Reporting Information [Line Items]
Operating Revenues	2,079	1,983	4,166	3,952
External Operating Revenues | Wireline | Global Enterprise Core
Segment Reporting Information [Line Items]
Operating Revenues	1,549	1,837	3,209	3,719
External Operating Revenues | Wireline | Global Enterprise
Segment Reporting Information [Line Items]
Operating Revenues	3,628	3,820	7,375	7,671
External Operating Revenues | Wireline | Global Wholesale
Segment Reporting Information [Line Items]
Operating Revenues	1,437	1,562	2,908	3,154
External Operating Revenues | Wireline | Other
Segment Reporting Information [Line Items]
Operating Revenues	115	130	218	253
External Operating Revenues | Total Segments
Segment Reporting Information [Line Items]
Operating Revenues	29,421	28,209	58,476	56,125
External Operating Revenues | Corporate, Eliminations and Other
Segment Reporting Information [Line Items]
Operating Revenues	365	343	730	669
Intersegment Revenues | Wireless
Segment Reporting Information [Line Items]
Operating Revenues	24	22	51	45
Intersegment Revenues | Wireline
Segment Reporting Information [Line Items]
Operating Revenues	265	277	536	556
Intersegment Revenues | Total Segments
Segment Reporting Information [Line Items]
Operating Revenues	289	299	587	601
Intersegment Revenues | Corporate, Eliminations and Other
Segment Reporting Information [Line Items]
Operating Revenues	$ (289)	$ (299)	$ (587)	$ (601)