Employee Benefits (Components of Company Plan Benefit Expense) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 30, 2013	Mar. 31, 2012
Pension [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 34	$ 28
Interest cost	50	51
Expected return on plan assets	(90)	(86)
Amortization of unrecognized prior service cost (credit)	4	4
Total expense	(2)	(3)
Other Nonpension Postretirement [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	9	6
Interest cost	12	13
Expected return on plan assets	(22)	(21)
Amortization of unrecognized prior service cost (credit)	(1)	0
Total expense	(2)	(2)
Postemployment [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	2	2
Interest cost	1	1
Recognized net loss	2	1
Total expense	$ 5	$ 4