Employee Benefit Plans (Cash Flows) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 28, 2012	Dec. 30, 2011
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract]
2013	$ 173
2014	177
2015	178
2016	180
2017	181
2018-2022	916
Total	1,805
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract]
2013	41
2014	40
2015	38
2016	36
2017	34
2018-2022	143
Total	332
Qualified Employer Contributions [Member] | Pension Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer Contributions	275	0
Contributions by employer, required minimum amount	25
Qualified Employer Contributions [Member] | Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer Contributions	$ 0	$ 0