Employee Benefit Plans (Benefit obligation, Plan Assets and Funded Status) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 28, 2012	Dec. 30, 2011	Dec. 31, 2010
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets at End of Plan Year	$ 2,294	$ 1,850
Pension Plans, Defined Benefit [Member]
Actuarial Present Value of Benefit Obligation [Abstract]
Accumulated Benefit Obligation	2,806	2,516
Projected Benefit Obligation	2,954	2,668	2,487
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Projected Benefit Obligation at Beginning of Year	2,668	2,487
Service Cost	44	40	41
Interest Cost	123	121	122
Plan Participants Contributions	0	0
Plan Amendments	0	0
Actuarial Net (Gains) Losses	274	175
Benefits Paid	(155)	(155)
Benefit Obligation at End of Plan Year	2,954	2,668	2,487
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets at Beginning of Plan Year	1,850	1,851
Actual Return on Plan Assets	311	141
Plan Participants Contributions	0	0
Benefits Paid	(155)	(155)
Fair Value of Plan Assets at End of Plan Year	2,294	1,850	1,851
Funded Status at End of Plan Year	(660)	(818)
Other Postretirement Benefit Plans, Defined Benefit [Member]
Actuarial Present Value of Benefit Obligation [Abstract]
Projected Benefit Obligation	415	388	383
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Projected Benefit Obligation at Beginning of Year	388	383
Service Cost	4	2	5
Interest Cost	16	11	20
Plan Participants Contributions	8	7
Plan Amendments	(1)	0
Actuarial Net (Gains) Losses	43	32
Benefits Paid	(43)	(47)
Benefit Obligation at End of Plan Year	415	388	383
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets at Beginning of Plan Year	0	0
Actual Return on Plan Assets	0	0
Plan Participants Contributions	8	7
Benefits Paid	(43)	(47)
Fair Value of Plan Assets at End of Plan Year	0	0	0
Funded Status at End of Plan Year	(415)	(388)
Qualified Employer Contributions [Member] | Pension Plans, Defined Benefit [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Employer Contributions	275	0
Qualified Employer Contributions [Member] | Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Employer Contributions	0	0
Non-qualified Employer Contributions [Member] | Pension Plans, Defined Benefit [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Employer Contributions	13	13
Non-qualified Employer Contributions [Member] | Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Employer Contributions	$ 35	$ 40