Casualty, Environmental and Other Reserves (Casualty) (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 28, 2012 claims	Dec. 30, 2011	Dec. 31, 2010		Jun. 01, 2010	May 31, 2010
Loss Contingencies [Line Items]
Change in estimate recorded to adjust casualty reserves			$ 49	[1]
Casualty [Member]
Loss Contingencies [Line Items]
Self-insured retention amount per injury					50	25
Individual claims expected to exceed self-insured retention amount	0
Change in estimate recorded to adjust casualty reserves	0	0	49	[1]
After-tax effect on earnings from continuing operations and net earnings			$ 30
After-tax effect on earnings per share			$ 0.03

[1] Change in estimate in 2010 is the result of continued safety improvements and decreasing claim trends for both personal injury and occupational injuries.