Changes in Balance of Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 25, 2016	Sep. 27, 2015	Sep. 25, 2016		Sep. 27, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance				$ (11,444)		$ (11,870)
Other comprehensive loss before reclassifications				(46)		(88)
Amounts reclassified from AOCL
Recognition of net actuarial losses	[1]			703		831
Amortization of net prior service credits	[1]			(182)		(194)
Recognition of net prior service credits from divestiture of IS&GS segment		$ (134)		(134)	[2]
Other	[2]			112
Total reclassified from AOCL				499		637
Other comprehensive income, net of tax		113	$ 135	453		549
Ending balance		(10,991)	(11,321)	(10,991)		(11,321)
Postretirement Benefit Plan Adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance				(11,314)		(11,813)
Amounts reclassified from AOCL
Recognition of net actuarial losses		234	277	703	[1]	831	[1]
Amortization of net prior service credits		(59)	(65)	(182)	[1]	(194)	[1]
Recognition of net prior service credits from divestiture of IS&GS segment	[2]			(134)
Total reclassified from AOCL		175	212	387		637
Other comprehensive income, net of tax				387		637
Ending balance		(10,927)	(11,176)	(10,927)		(11,176)
Other, net
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance				(130)		(57)
Other comprehensive loss before reclassifications				(46)		(88)
Amounts reclassified from AOCL
Other	[2]			112
Total reclassified from AOCL				112
Other comprehensive income, net of tax				66		(88)
Ending balance		$ (64)	$ (145)	$ (64)		$ (145)

[1] Reclassifications from AOCL, net of tax, related to our postretirement benefit plans were recorded as a component of net periodic benefit cost for each period presented (Note 7). These amounts include $175 million and $212 million for the quarters ended September 25, 2016 and September 27, 2015, which are composed of the recognition of net actuarial losses of $234 million and $277 million for the quarters ended September 25, 2016 and September 27, 2015 and the amortization of net prior service (credits) costs of $(59) million and $(65) million for the quarters ended September 25, 2016 and September 27, 2015.

[2] Associated with the divestiture of the IS&GS business segment and included in net gain on divestiture of discontinued operations.