Properties (Railroad Assets and Capital Expenditure) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended			1 Months Ended	12 Months Ended					12 Months Ended		12 Months Ended		12 Months Ended
	Dec. 30, 2011	Dec. 31, 2010	Dec. 25, 2009	Dec. 30, 2011 SunRail Transaction - Sale of Corridor [Member]	Dec. 30, 2011 Road - Total [Member] years	Dec. 31, 2010 Road - Total [Member] years	Dec. 25, 2009 Road - Total [Member] Change in Accounting Method Accounted for as Change in Estimate [Member]	Dec. 30, 2011 Road - Ties [Member] categories	Dec. 31, 2010 Road - Ties [Member]	Dec. 30, 2011 Road - System Roadway Machinery [Member] years	Dec. 31, 2010 Road - System Roadway Machinery [Member]	Dec. 30, 2011 Road - Grading [Member] years	Dec. 31, 2010 Road - Grading [Member]	Dec. 30, 2011 Total Equipment [Member] years	Dec. 31, 2010 Total Equipment [Member] years	Dec. 31, 2010 Total Equipment [Member] Change in Accounting Method Accounted for as Change in Estimate [Member]	Dec. 30, 2011 Technology Assets [Member] years	Dec. 30, 2011 Equipment - Work Equipment and Other [Member] years	Dec. 31, 2010 Equipment - Work Equipment and Other [Member]	Dec. 30, 2011 Minimum [Member] categories
Railroad Assets [Abstract]
Percentage of assets depreciated under the group-life method (in hundredths)	85.00%	85.00%
Property, Plant and Equipment, Gross	$ 33,704	$ 32,065			$ 22,379	$ 20,906		$ 4,126	$ 3,896	$ 3,038	$ 2,527	$ 2,379	$ 2,368	$ 8,621	$ 7,443			$ 1,345	$ 436
Number of depreciable asset categories for railroad assets								18												130
Property, Plant and Equipment, Life Studies, Frequency Period					6									3
Estimated Useful Life, Minimum (in years)					6	6				6				5	5		6
Estimated Useful Life, Maximum (in years)					80	80						80		35	35			35
Abnormal gains and losses from large groups of assets being removed from service		30	0	(14)
Annual depreciation expense	976	947	903
Change in depreciation expense due to life studies assessment							$ 18									$ 11
Capital Expenditures [Abstract]
Percentage of labor costs relating to the deconstruction of old track (In hundredths)	20.00%
Percentage of labor costs relating to the installation of new track (In hundredths)	80.00%