Reconciliation of Total Reportable Segments Operating Income to Consolidated Income before Provision for Income Taxes (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Segment Reporting Information [Line Items]
Gain on spectrum license transactions (Note 2)	$ 278		$ 278
Pension remeasurement (Note 7)			237
Litigation settlements (Note 10)		(384)		(384)
Operating income	7,128	5,483	19,905	16,329
Equity in earnings of unconsolidated businesses	19	62	134	237
Other income, net	20	10	84	63
Interest expense	(555)	(632)	(1,606)	(1,996)
Income Before Provision For Income Taxes	6,612	4,923	18,517	14,633
Corporate, Eliminations and Other
Segment Reporting Information [Line Items]
Operating income	(191)	(221)	(620)	(650)
Total Segments
Segment Reporting Information [Line Items]
Operating income	$ 7,041	$ 6,088	$ 20,010	$ 17,363