Changes in Balance of Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 28, 2015	Jun. 29, 2014	Jun. 28, 2015		Jun. 29, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance				$ (11,870)		$ (9,601)
Net actuarial losses	[1]					(3,778)
Prior service credits	[1]					3,043
Other						15
Total other comprehensive (loss) income before reclassifications				(11)		(720)
Amounts reclassified from AOCL
Recognition of net actuarial losses	[2]			554		306
Amortization of net prior service cost (credits)	[2]			(129)		28
Other						3
Total reclassified from AOCL				425		337
Other comprehensive income (loss), net of tax		$ 259	$ (547)	414		(383)
Ending balance		(11,456)	(9,984)	(11,456)		(9,984)
Postretirement Benefit Plan Adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance				(11,813)		(9,649)
Net actuarial losses	[1]					(3,778)
Prior service credits	[1]					3,043
Total other comprehensive (loss) income before reclassifications						(735)
Amounts reclassified from AOCL
Recognition of net actuarial losses		277	153	554	[2]	306	[2]
Amortization of net prior service cost (credits)		(64)	14	(129)	[2]	28	[2]
Total reclassified from AOCL		213	167	425		334
Other comprehensive income (loss), net of tax				425		(401)
Ending balance		(11,388)	(10,050)	(11,388)		(10,050)
Other, net
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance				(57)		48
Other						15
Total other comprehensive (loss) income before reclassifications				(11)		15
Amounts reclassified from AOCL
Other						3
Total reclassified from AOCL						3
Other comprehensive income (loss), net of tax				(11)		18
Ending balance		$ (68)	$ 66	$ (68)		$ 66

[1] Changes in AOCL before reclassifications in 2014 related to our postretirement benefit plans include net actuarial losses from the re-measurement of substantially all our defined benefit pension plans in June 2014 and prior service credits from the June 2014 plan amendments to freeze future retirement benefits in certain of our qualified and nonqualified defined benefit pension plans for non-union employees.

[2] Reclassifications from AOCL related to our postretirement benefit plans were recorded as a component of net periodic benefit cost for each period presented (Note 6). These amounts include $213 million and $167 million for the quarters ended June 28, 2015 and June 29, 2014, which are comprised of the recognition of net actuarial losses of $277 million and $153 million for the quarters ended June 28, 2015 and June 29, 2014 and the amortization of net prior service (credits) costs of $(64) million and $14 million for the quarters ended June 28, 2015 and June 29, 2014.