Nonpension Postretirement and Postemployment Benefits (Components of Postretirement Expense, Postretirement) (Details) (Nonpension Postretirement [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Jan. 01, 2011	Jan. 02, 2010
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 23	$ 20
Interest cost	62	64
Postretirement benefit expense	28	48	40
Estimated net experience loss for defined benefit pension plans, expected to be amortized	16
Amortization prior service cost	3
Defined Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	23	20	18
Interest cost	62	64	65
Expected return on plan assets	(88)	(64)	(68)
Amortization of unrecognized prior service cost	(3)	(3)	(2)
Recognized net loss	20	17	13
Postretirement benefit expense	14	34	26
Defined Contribution Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Postretirement benefit expense	$ 14	$ 14	$ 14