Properties (Detail of Net Properties) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 27, 2013		Dec. 28, 2012
Property, Plant and Equipment, Net, by Type [Abstract]
Cost	$ 37,184	[1]	$ 35,279	[1]
Accumulated Depreciation	(9,893)	[1]	(9,229)	[1]
Properties - Net	27,291		26,050	[1]
Road - Total [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Cost	24,618		23,419
Accumulated Depreciation	(5,592)		(5,153)
Properties - Net	19,026		18,266
Road - Rail and Other Track Material [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Cost	6,452		6,177
Accumulated Depreciation	(1,270)		(1,131)
Properties - Net	5,182		5,046
Annual Depreciation Rate	2.90%		2.90%
Depreciation Method	Group Life		Group Life
Road - Ties [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Cost	4,534		4,287
Accumulated Depreciation	(947)		(861)
Properties - Net	3,587		3,426
Annual Depreciation Rate	4.00%		4.00%
Depreciation Method	Group Life		Group Life
Road - Grading [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Cost	2,425		2,407
Accumulated Depreciation	(448)		(414)
Properties - Net	1,977		1,993
Annual Depreciation Rate	1.50%		1.50%
Depreciation Method	Group Life		Group Life
Road - Ballast [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Cost	2,612		2,528
Accumulated Depreciation	(645)		(624)
Properties - Net	1,967		1,904
Annual Depreciation Rate	2.80%		2.80%
Depreciation Method	Group Life		Group Life
Road - Bridges, Trestles, and Culverts [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Cost	2,008		1,962
Accumulated Depreciation	(250)		(224)
Properties - Net	1,758		1,738
Annual Depreciation Rate	1.60%		1.60%
Depreciation Method	Group Life		Group Life
Road - Signals and Interlockers [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Cost	1,922		1,787
Accumulated Depreciation	(291)		(302)
Properties - Net	1,631		1,485
Annual Depreciation Rate	3.40%		3.40%
Depreciation Method	Group Life		Group Life
Road - Buildings [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Cost	1,011		926
Accumulated Depreciation	(355)		(316)
Properties - Net	656		610
Annual Depreciation Rate	2.50%		2.50%
Depreciation Method	Group Life		Group Life
Road - Other [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Cost	3,654		3,345
Accumulated Depreciation	(1,386)		(1,281)
Properties - Net	2,268		2,064
Annual Depreciation Rate	4.70%		4.70%
Depreciation Method	Group Life		Group Life
Total Equipment [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Cost	9,764		9,301
Accumulated Depreciation	(4,225)		(4,008)
Properties - Net	5,539		5,293
Equipment - Locomotive [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Cost	4,987		4,747
Accumulated Depreciation	(2,176)		(2,079)
Properties - Net	2,811		2,668
Annual Depreciation Rate	3.60%		3.60%
Depreciation Method	Group Life		Group Life
Equipment - Freight Cars [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Cost	3,111		3,088
Accumulated Depreciation	(1,135)		(1,119)
Properties - Net	1,976		1,969
Annual Depreciation Rate	3.10%		3.10%
Depreciation Method	Group Life		Group Life
Equipment - Work Equipment and Other [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Cost	1,666		1,466
Accumulated Depreciation	(914)		(810)
Properties - Net	752		656
Annual Depreciation Rate	7.10%		7.10%
Depreciation Method	Group Life		Group Life
Land [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Cost	1,842		1,745
Properties - Net	1,842		1,745
Construction in Progress [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Cost	854		602
Properties - Net	854		602
Other properties [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Cost	106		212
Accumulated Depreciation	(76)		(68)
Properties - Net	$ 30		$ 144
Depreciation Method	Straight Line		Straight Line
Minimum [Member] | Road - Total [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated useful life	6 years		6 years
Minimum [Member] | Road - Other [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated useful life	6 years
Minimum [Member] | Total Equipment [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated useful life	5 years		5 years
Minimum [Member] | Other properties [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated useful life	4 years		4 years
Maximum [Member] | Road - Total [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated useful life	80 years		80 years
Maximum [Member] | Road - Grading [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated useful life	80 years
Maximum [Member] | Total Equipment [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated useful life	38 years		38 years
Maximum [Member] | Equipment - Work Equipment and Other [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated useful life	38 years
Maximum [Member] | Other properties [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated useful life	30 years		30 years

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