XML 55 R27.htm IDEA: XBRL DOCUMENT
v3.3.0.814

Nature of Operations and Significant Accounting Policies - Narrative (Details) mi in Thousands, $ in Millions | 3 Months Ended | 9 Months Ended |
--- | --- | --- | ---
Sep. 25, 2015 USD ($) state mi | Sep. 26, 2014 | Sep. 25, 2015 USD ($) state mi | Sep. 26, 2014 | Dec. 26, 2014 USD ($)
Background |  |  |  |  |
Total number of rail route miles | 21 |  | 21 |  |
Number of states rail network serves | state | 23 |  | 23 |  |
Fiscal Year |  |  |  |  |
Number of days in fiscal year |  |  | 364 days | 364 days |
Number of days in fiscal quarter | 91 days | 91 days |  |  |
Number of days in fiscal quarter YTD |  |  | 273 days | 273 days |
Allowance for Doubtful Accounts |  |  |  |  |
Allowance for doubtful accounts | $ | $ 39 |  | $ 39 |  | $ 41

X
- Definition Allowance for Doubtful Accounts [Abstract] + References No definition available. + Details
Name: | csx_AllowanceForDoubtfulAccountsAbstract
Namespace Prefix: | csx_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Background [Abstract] + References No definition available. + Details
Name: | csx_BackgroundAbstract
Namespace Prefix: | csx_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Fiscal Year [Abstract] + References No definition available. + Details
Name: | csx_FiscalYearAbstract
Namespace Prefix: | csx_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of Weeks Fiscal Quarter + References No definition available. + Details
Name: | csx_NumberofWeeksFiscalQuarter
Namespace Prefix: | csx_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of Weeks Fiscal Quarter YTD + References No definition available. + Details
Name: | csx_NumberofWeeksFiscalQuarterYTD
Namespace Prefix: | csx_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of Weeks Fiscal Year Reporting Calendar + References No definition available. + Details
Name: | csx_NumberofWeeksFiscalYearReportingCalendar
Namespace Prefix: | csx_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Rail Route Network, Distance + References No definition available. + Details
Name: | csx_RailRouteNetworkDistance
Namespace Prefix: | csx_
Data Type: | num:lengthItemType
Balance Type: | na
Period Type: | instant

X
- Definition A valuation allowance for trade and other receivables due to an Entity within one year (or the normal operating cycle, whichever is longer) that are expected to be uncollectible. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.4) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=49124121&loc=d3e5074-111524 + Details
Name: | us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The number of states the entity operates in as of the balance sheet date. + References No definition available. + Details
Name: | us-gaap_NumberOfStatesInWhichEntityOperates
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant