Properties (Railroad Assets, Non-Railroad Assets, and Capital Expenditure) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 27, 2013		Dec. 28, 2012		Dec. 30, 2011
Railroad Assets [Abstract]
Percentage of assets depreciated under the group-life method	86.00%
Total fixed assets	$ 37,184	[1]	$ 35,279	[1]
Annual depreciation expense	1,104		1,059	[1]	976	[1]
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%
Road - Total [Member]
Railroad Assets [Abstract]
Total fixed assets	24,618		23,419
Life studies, frequency period	6 years
Road - Ties [Member]
Railroad Assets [Abstract]
Total fixed assets	4,534		4,287
Number of depreciable asset categories for railroad assets	18
Road - System Roadway Machinery [Member]
Railroad Assets [Abstract]
Total fixed assets	3,654		3,345
Road - Grading [Member]
Railroad Assets [Abstract]
Total fixed assets	2,425		2,407
Total Equipment [Member]
Railroad Assets [Abstract]
Total fixed assets	9,764		9,301
Life studies, frequency period	3 years
Equipment - Work Equipment and Other [Member]
Railroad Assets [Abstract]
Total fixed assets	1,666		1,466
Abnormal gain (loss) on operating property [Member]
Railroad Assets [Abstract]
Abnormal gains and losses	65		104		14
Gain (loss) on non-operating property [Member]
Railroad Assets [Abstract]
Abnormal gains and losses			$ 57
Minimum [Member]
Railroad Assets [Abstract]
Number of depreciable asset categories for railroad assets	130
Minimum [Member] | Road - Total [Member]
Railroad Assets [Abstract]
Estimated useful life	6 years		6 years
Minimum [Member] | Road - System Roadway Machinery [Member]
Railroad Assets [Abstract]
Estimated useful life	6 years
Minimum [Member] | Total Equipment [Member]
Railroad Assets [Abstract]
Estimated useful life	5 years		5 years
Minimum [Member] | Technology Assets [Member]
Railroad Assets [Abstract]
Estimated useful life	6 years
Maximum [Member] | Road - Total [Member]
Railroad Assets [Abstract]
Estimated useful life	80 years		80 years
Maximum [Member] | Road - Grading [Member]
Railroad Assets [Abstract]
Estimated useful life	80 years
Maximum [Member] | Total Equipment [Member]
Railroad Assets [Abstract]
Estimated useful life	38 years		38 years
Maximum [Member] | Equipment - Work Equipment and Other [Member]
Railroad Assets [Abstract]
Estimated useful life	38 years

[1] See the revision of prior period financial statements in Note 1. Nature of Operations and Significant Accounting Policies.