Changes in Accumulated Other Comprehensive Loss, Net of Tax (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Apr. 02, 2016	Mar. 28, 2015	Apr. 02, 2016	Mar. 28, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI, Beginning Balance	$ (2,469)	$ (1,880)	$ (2,421)	$ (1,968)
Unrealized gains (losses) arising during the period	(130)	78	(154)	163
Reclassifications of net (gains) losses to net income	0	(41)	(24)	(38)
AOCI, Ending Balance	$ (2,599)	$ (1,843)	$ (2,599)	$ (1,843)
Estimated tax rate	37.00%	37.00%	37.00%	37.00%
Investments, net
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI, Beginning Balance	$ 10	$ 84	$ 13	$ 100
Unrealized gains (losses) arising during the period	(1)	(24)	(4)	(40)
Reclassifications of net (gains) losses to net income	0	(30)	0	(30)
AOCI, Ending Balance	9	30	9	30
Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI, Beginning Balance	309	339	334	204
Unrealized gains (losses) arising during the period	(162)	183	(121)	359
Reclassifications of net (gains) losses to net income	(42)	(54)	(108)	(95)
AOCI, Ending Balance	105	468	105	468
Unrecognized Pension and Postretirement Medical Expense
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI, Beginning Balance	(2,455)	(2,152)	(2,497)	(2,196)
Unrealized gains (losses) arising during the period	(2)	(9)	(2)	(9)
Reclassifications of net (gains) losses to net income	42	43	84	87
AOCI, Ending Balance	(2,415)	(2,118)	(2,415)	(2,118)
Foreign Currency Translation and Other
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI, Beginning Balance	(333)	(151)	(271)	(76)
Unrealized gains (losses) arising during the period	35	(72)	(27)	(147)
Reclassifications of net (gains) losses to net income	0	0	0	0
AOCI, Ending Balance	$ (298)	$ (223)	$ (298)	$ (223)