Changes in Accumulated Other Comprehensive Loss, Net of Tax (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Sep. 29, 2012		Oct. 01, 2011		Oct. 02, 2010
Accumulated Other Comprehensive Income (Loss) [Line Items]
Market value adjustments, investments, Beginning Balance	$ 6		$ 7		$ (2)
Unrealized gains (losses) arising during the period, investments	4		2		8
Reclassifications of realized net (gains) losses to net income, investments	(7)		(3)		1
Market value adjustments, investments, Ending Balance	3		6		7
Market value adjustments, investments cash flow hedges, Beginning Balance	(54)		(102)		20
Unrealized gains (losses) arising during the period, cash flow hedges	38		(72)		(118)
Reclassifications of realized net (gains) losses to net income, cash flow hedges	(36)		120		(4)
Market value adjustments, investments cash flow hedges, Ending Balance	(52)		(54)		(102)
Unrecognized pension and post-retirement medical expense, Beginning Balance	(2,625)		(1,866)		(1,767)
Unrealized gains (losses) arising during the period, pension and post-retirement medical expense	(829)		(915)		(208)
Reclassifications of realized net (gains) losses to net income, pension and post-retirement medical expense	220		156		109
Unrecognized pension and post-retirement medical expense, Ending Balance	(3,234)		(2,625)		(1,866)
Foreign currency translation and other, Beginning Balance	43		80		105
Unrealized gains (losses) arising during the period, foreign currency translation and other	(60)		(37)		(25)
Reclassifications of realized net (gains) losses to net income, foreign currency translation and other	34
Foreign currency translation and other, Ending Balance	17		43		80
Accumulated other comprehensive income, net of tax, Beginning Balance	(2,630)	[1]	(1,881)	[1]	(1,644)	[1]
Unrealized gains (losses) arising during the period, total	(847)	[1]	(1,022)	[1]	(343)	[1]
Reclassifications of realized net (gains) losses to net income, total	211	[1]	273	[1]	106	[1]
Accumulated other comprehensive income, net of tax, Ending Balance	$ (3,266)	[1]	$ (2,630)	[1]	$ (1,881)	[1]

[1] Accumulated other comprehensive income (loss) and components of other comprehensive income (loss) are recorded net of tax using a 37% estimated statutory tax rate.