Changes in Accumulated Other Comprehensive Loss, Net of Tax (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 27, 2015	Jun. 28, 2014	Jun. 27, 2015	Jun. 28, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI, Beginning Balance	$ (1,843)	$ (1,206)	$ (1,968)	$ (1,187)
Unrealized gains (losses) arising during the period	9	24	172	82
Reclassifications of net (gains) losses to net income	(70)	13	(108)	(64)
AOCI, Ending Balance	$ (1,904)	$ (1,169)	$ (1,904)	$ (1,169)
Estimated tax rate	37.00%	37.00%	37.00%	37.00%
Investments, net
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI, Beginning Balance	$ 30	$ 40	$ 100	$ 95
Unrealized gains (losses) arising during the period	9	29	(31)	69
Reclassifications of net (gains) losses to net income	(20)	(1)	(50)	(96)
AOCI, Ending Balance	19	68	19	68
Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI, Beginning Balance	468	50	204	83
Unrealized gains (losses) arising during the period	(16)	(24)	343	(26)
Reclassifications of net (gains) losses to net income	(93)	(10)	(188)	(41)
AOCI, Ending Balance	359	16	359	16
Unrecognized Pension and Postretirement Medical Expense
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI, Beginning Balance	(2,118)	(1,207)	(2,196)	(1,271)
Unrealized gains (losses) arising during the period	0	0	(9)	15
Reclassifications of net (gains) losses to net income	43	24	130	73
AOCI, Ending Balance	(2,075)	(1,183)	(2,075)	(1,183)
Foreign Currency Translation and Other
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI, Beginning Balance	(223)	(89)	(76)	(94)
Unrealized gains (losses) arising during the period	16	19	(131)	24
Reclassifications of net (gains) losses to net income	0	0	0	0
AOCI, Ending Balance	$ (207)	$ (70)	$ (207)	$ (70)