Reconciliation of Total Reportable Segments Operating Income to Consolidated Income before Provision for Income Taxes (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Segment Reporting Information [Line Items]
Pension and benefit charges (Note 8)	$ (3,550)		$ (3,715)
Gain on spectrum license transaction (Note 2)			142
Operating Income	4,554	$ 7,821	12,496	$ 15,781
Equity in losses of unconsolidated businesses	(20)	(18)	(40)	(52)
Other income and (expense), net	(1,826)	32	(1,794)	107
Interest expense	(1,013)	(1,208)	(2,201)	(2,540)
Income Before Provision For Income Taxes	1,695	6,627	8,461	13,296
Access Line Sale with Frontier
Segment Reporting Information [Line Items]
Gain on access line sale (Note 2)	1,007		1,007
Operating Segments
Segment Reporting Information [Line Items]
Operating Income	7,554	7,497	15,367	15,087
Corporate and Other
Segment Reporting Information [Line Items]
Operating Income	$ (457)	(417)	(966)	(698)
Operating Income Generated By Assets Sold
Segment Reporting Information [Line Items]
Operating Income		$ 741	$ 661	$ 1,392