Reconciliation of Segment Assets (Detail) - USD ($) $ in Millions	Jun. 30, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Assets	$ 252,978	$ 244,180
Operating Segments
Segment Reporting Information [Line Items]
Assets	290,053	278,024
Operating Segments | Wireless
Segment Reporting Information [Line Items]
Assets	222,275	211,345
Operating Segments | Wireline
Segment Reporting Information [Line Items]
Assets	67,778	66,679
Corporate and Other
Segment Reporting Information [Line Items]
Assets	225,651	213,787
Eliminations
Segment Reporting Information [Line Items]
Assets	$ (262,726)	$ (247,631)