Nature of Operations and Significant Accounting Policies (Business) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 28, 2012 states mi railroads employees	Sep. 28, 2012	Jun. 29, 2012	Mar. 30, 2012	Dec. 30, 2011	Sep. 30, 2011	Jul. 01, 2011	Apr. 01, 2011	Dec. 28, 2012 employees states mi railroads	Dec. 30, 2011	Dec. 31, 2010
Revenue from External Customer [Line Items]
Entity Number of Employees	32,000								32,000
Number of Union Employees									27,000
Total number of rail route miles	21,000								21,000
Rail network states number	23								23
Number of short-line and regional railroads served	240								240
Revenue	$ 2,884	$ 2,894	$ 3,012	$ 2,966	$ 2,951	$ 2,963	$ 3,019	$ 2,810	$ 11,756	$ 11,743	$ 10,636
Minimum [Member]
Revenue from External Customer [Line Items]
Number of ocean, river and lake ports serviced	70								70
Merchandise business [Member]
Revenue from External Customer [Line Items]
Number of carloads									2,700,000
Percentage of total revenue									57.00%
Percentage of total volume									42.00%
Coal business [Member]
Revenue from External Customer [Line Items]
Number of carloads									1,300,000
Percentage of total revenue									27.00%
Percentage of total volume									20.00%
Intermodal business [Member]
Revenue from External Customer [Line Items]
Percentage of total revenue									14.00%
Percentage of total volume									38.00%
Minimum number of terminals	50								50
Other business [Member]
Revenue from External Customer [Line Items]
Percentage of total revenue									2.00%