Income Taxes (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended						4 Months Ended		12 Months Ended
	Sep. 28, 2014	Jul. 06, 2014	Apr. 13, 2014	Sep. 29, 2013	Jul. 07, 2013	Apr. 14, 2013	Jan. 19, 2014	Jan. 20, 2013	Sep. 28, 2014	Sep. 29, 2013	Sep. 30, 2012
Components of income tax expense
Current federal income tax									$ 359	$ 321	$ 234
Current state income tax									82	73	53
Current foreign income tax									2	3	4
Total current tax									443	397	291
Deferred federal income tax									(66)	(44)	1
Deferred state income tax									(10)	(10)	(6)
Deferred foreign income tax									0	0	0
Total deferred tax									(76)	(54)	(5)
Total income tax expense	79	96	91	74	88	89	101	92	367	343	286
Reconciliation of income tax expense to federal statutory rate
Federal income tax based on statutory rates									331	313	263
Increase (reduction) in income taxes resulting from:
Tax-exempt interest									(1)	(1)	(1)
Excess charitable contributions									(8)	(7)	(5)
Federal income tax credits									(3)	(2)	(2)
Other, net									2		1
Total federal income taxes									321	303	256
State income taxes									47	41	31
Foreign income taxes									(1)	(1)	(1)
Total income tax expense	79	96	91	74	88	89	101	92	367	343	286
Income Taxes Receivable, Current	$ 1			$ 7					$ 1	$ 7