Number of locomotives under the long-term maintenance program.

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- Definition

Percentage of locomotive fleet currently covered under a long-term maintenance program.

+ References

No definition available.

+ Details

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- Definition

Maintenance costs incurred and directly related to services rendered by an entity during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.2(d))

-URI http://asc.fasb.org/extlink&oid=6880815&loc=d3e20235-122688

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- Definition

Amount of the fixed and determinable portion of the unrecorded unconditional purchase obligation maturing in the fifth fiscal year following the latest fiscal year.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 440

-SubTopic 10

-Section 50

-Paragraph 4

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6394976&loc=d3e25336-109308

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 47

-Paragraph 7

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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- Definition

Amount of the fixed and determinable portion of the unrecorded unconditional purchase obligation maturing in the next fiscal year following the latest fiscal year.

+ References

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- Definition

Amount of the fixed and determinable portion of the unrecorded unconditional purchase obligation maturing in the four fiscal year following the latest fiscal year.

+ References

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- Definition

Amount of the fixed and determinable portion of the unrecorded unconditional purchase obligation maturing in the second fiscal year following the latest fiscal year.

+ References

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- Definition

Amount of the fixed and determinable portion of the unrecorded unconditional purchase obligation maturing in the third fiscal year following the latest fiscal year.

+ References

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- Definition

Amount of the unrecorded obligation to transfer funds in the future for fixed or minimum amounts or quantities of goods or services at fixed or minimum prices (for example, as in take-or-pay contracts or throughput contracts).

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- Definition

Amount of the fixed and determinable portion of the unrecorded unconditional purchase obligation maturing after the fifth fiscal year following the latest fiscal year.

+ References

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Commitments and Contingencies (Purchase Commitments) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 28, 2012	Dec. 30, 2011	Dec. 31, 2010
Unrecorded Unconditional Purchase Obligation [Line Items]
Percentage of Locomotive Fleet Under Long-Term Maintenance Program	44.00%
Amounts Paid	$ 287	$ 281	$ 252
Number of locomotives under the long term maintenance plan	1,899	1,928	1,859
Unrecorded Unconditional Purchase Obligation [Abstract]
2013	559
2014	406
2015	306
2016	271
2017	252
Thereafter	1,887
Total	3,681
Locomotive Purchase Obligations [Member]
Unrecorded Unconditional Purchase Obligation [Abstract]
2013	472
2014	347
2015	263
2016	257
2017	247
Thereafter	1,833
Total	3,419
Other Purchase Obligations [Member]
Unrecorded Unconditional Purchase Obligation [Abstract]
2013	87
2014	59
2015	43
2016	14
2017	5
Thereafter	54
Total	$ 262