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Number of depreciable asset categories to account for depreciation expense for the railroad assets that are depreciated under the group life method.

+ References

No definition available.

+ Details

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- Definition

Assets depreciated under the group-life method of total fixed assets on a gross basis. Does not include other assets which are depreciated on a straight line basis.

+ References

No definition available.

+ Details

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- Definition

Percentage of labor costs relating to the deconstruction of old track based upon an analysis of track replacement process.

+ References

No definition available.

+ Details

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- Definition

Percentage of labor costs relating to the installation of new track based upon an analysis of track replacement process.

+ References

No definition available.

+ Details

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Namespace Prefix:	csx_
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- Definition

The frequency with which life studies are required, by Surface Transporation Board (STB) to be performed.

+ References

No definition available.

+ Details

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- Details

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- Definition

The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 28

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

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

-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 12

-Paragraph 5

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3602-108585

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- Definition

The gains (losses) included in results of operations resulting from the sale or disposal of property, plant and equipment, which do not qualify for treatment as discontinued operations. This item does not include any gain (loss) recognized on the sale of oil and gas property or timber property.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 144

-Paragraph 37, 41, 42, 43, 45

-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.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 360

-SubTopic 10

-Section 50

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6391110&loc=d3e2941-110230

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-Name Accounting Standards Codification

-Topic 205

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6360339&loc=d3e1361-107760

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-Name Accounting Standards Codification

-Topic 360

-SubTopic 10

-Section 45

-Paragraph 5

-URI http://asc.fasb.org/extlink&oid=8077374&loc=d3e2443-110228

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- Definition

The gains (losses) included in results of operations resulting from the sale or disposal of other assets.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3602-108585

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 28

-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

Gross amount of long-lived physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

+ References

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

-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 12

-Paragraph 5

-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.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 360

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (b)

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.13)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

+ References

No definition available.

+ Details

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Properties (Railroad Assets, Non-Railroad Assets, and Capital Expenditure) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 28, 2012	Dec. 30, 2011	Dec. 31, 2010
Railroad Assets [Abstract]
Percentage of assets depreciated under the group-life method	85.00%	85.00%
Total fixed assets	$ 35,279	$ 33,704
Abnormal gains and losses	104	14	(30)
Annual depreciation expense	1,059	976	947
Gain on sale of other assets	57
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	23,419	22,379
Life studies, frequency period	6 years
Road - Ties [Member]
Railroad Assets [Abstract]
Total fixed assets	4,287	4,126
Number of depreciable asset categories for railroad assets	18
Road - System Roadway Machinery [Member]
Railroad Assets [Abstract]
Total fixed assets	3,345	3,038
Road - Grading [Member]
Railroad Assets [Abstract]
Total fixed assets	2,407	2,379
Total Equipment [Member]
Railroad Assets [Abstract]
Total fixed assets	9,301	8,621
Life studies, frequency period	3 years
Equipment - Work Equipment and Other [Member]
Railroad Assets [Abstract]
Total fixed assets	$ 1,466	$ 1,345
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	35 years
Maximum [Member] \| Equipment - Work Equipment and Other [Member]
Railroad Assets [Abstract]
Estimated useful life	38 years