Employee Benefits (Contributions to Employee Benefit Plans) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2012	Apr. 02, 2011	Dec. 31, 2011
Defined Benefit Plan Disclosure [Line Items]
Employer contributions to employee benefit plans	$ 25	$ 178	$ 192
Total current year projected employer contributions	51
Pension [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contributions to employee benefit plans	21	174	180
Total current year projected employer contributions	34
Nonpension Postretirement [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contributions to employee benefit plans	4	4	12
Total current year projected employer contributions	$ 17