Retirement Plans (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Jan. 01, 2011	Jan. 02, 2010
Other changes in plan assets and benefit obligations recognized in OCI
Net loss (gain) arising during the year	$ 527	$ 186	$ (6)
Pension Benefits [Member]
Net periodic benefit cost
Service cost	129	124	116
Interest cost	327	328	323
Expected return on plan assets	(393)	(385)	(404)
Amortization of prior service cost (credit)	16	16	18
Amortization of net loss	75	41	10
Curtailment and special termination charges	(1)	2	34
Net periodic benefit cost	153	126	97
Other changes in plan assets and benefit obligations recognized in OCI
Amortization of net loss	(75)	(41)	(10)
Net loss (gain) arising during the year	556	171	(58)
Amortization of prior service credit (cost)	(16)	(16)	(48)
Prior service cost (credit) arising during the year	7	5	26
Curtailments and settlements	1	(1)
Total recognized in OCI	473	118	(90)
Total recognized in net periodic benefit cost and OCI	626	244	7
Postretirement Benefits Other than Pensions [Member]
Net periodic benefit cost
Service cost	8	8	8
Interest cost	33	34	38
Amortization of prior service cost (credit)	(8)	(4)	(5)
Amortization of net loss	11	11	8
Curtailment and special termination charges			(5)
Net periodic benefit cost	44	49	44
Other changes in plan assets and benefit obligations recognized in OCI
Amortization of net loss	(11)	(11)	(8)
Net loss (gain) arising during the year	(17)		24
Amortization of prior service credit (cost)	8	4	10
Prior service cost (credit) arising during the year	(23)	(16)	2
Total recognized in OCI	(43)	(23)	28
Total recognized in net periodic benefit cost and OCI	$ 1	$ 26	$ 72