Description of the Business (Details)	12 Months Ended
Dec. 31, 2012
KCSR [Member]
Ownership Interests [Line Items]
Percentage of employees covered by collective bargaining agreements	80.00%
KCSM [Member]
Ownership Interests [Line Items]
Initial percentage of gross revenue payable under railroad Concession to Mexican Government	0.50%
Initial period of time for payments due under railroad Concession to Mexican Government	15 years
Date the percentage of revenue payable to the Mexican government increased under the Concession	Jun. 24, 2012
Percentage of gross revenue payable under railroad Concession to Mexican Government after initial fifteen year period	1.25%
MSLLC [Member]
Ownership Interests [Line Items]
Subsidiary ownership percentage by parent	70.00%
PCRC [Member]
Ownership Interests [Line Items]
Equity method ownership percentage	50.00%
Southern Capital [Member]
Ownership Interests [Line Items]
Equity method ownership percentage	50.00%
FTVM [Member]
Ownership Interests [Line Items]
Equity method ownership percentage	25.00%
PTC-220 [Member]
Ownership Interests [Line Items]
Equity method ownership percentage	14.00%
KCSM Servicios [Member]
Ownership Interests [Line Items]
Term of labor agreement with Mexican Railroad Union	50 years
Percentage of employees covered by labor agreement	80.00%
Maximum [Member] \| KCSM [Member]
Ownership Interests [Line Items]
Additional concession renewal period	50 years

Additional period that the concession from the Mexican government may be renewed under certain conditions.

No definition available.

Name:	ksu_AdditionalConcessionRenewalPeriod
Namespace Prefix:	ksu_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Date percentage of revenue payable to Mexican government increases under the concession.

+ References

No definition available.

+ Details

Name:	ksu_DatePercentageOfRevenuePayableToMexicanGovernmentIncreasesUnderConcession
Namespace Prefix:	ksu_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Employees Covered by Collective Bargaining Agreement, Percent

+ References

No definition available.

+ Details

Name:	ksu_EmployeesCoveredByCollectiveBargainingAgreementPercent
Namespace Prefix:	ksu_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Employees Covered by Labor Agreement, Percent

+ References

No definition available.

+ Details

Name:	ksu_EmployeesCoveredByLaborAgreementPercent
Namespace Prefix:	ksu_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Initial percentage of gross revenue payable under railroad concession to Mexican government.

+ References

No definition available.

+ Details

Name:	ksu_InitialPercentageOfGrossRevenuePayableUnderRailroadConcessionToMexicanGovernment
Namespace Prefix:	ksu_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Initial period of time for payments due under railroad concession to Mexican government.

+ References

No definition available.

+ Details

Name:	ksu_InitialPeriodOfTimeForPaymentsDueUnderRailroadConcessionToMexicanGovernment
Namespace Prefix:	ksu_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Labor Agreement Term

+ References

No definition available.

+ Details

Name:	ksu_LaborAgreementTerm
Namespace Prefix:	ksu_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	ksu_OwnershipInterestsLineItems
Namespace Prefix:	ksu_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of gross revenue payable under railroad concession to Mexican government after initial fifteen year period.

+ References

No definition available.

+ Details

Name:	ksu_PercentageOfGrossRevenuePayableUnderRailroadConcessionToMexicanGovernmentAfterInitialFifteenYearPeriod
Namespace Prefix:	ksu_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 159

-Paragraph 18

-Subparagraph f

-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 323

-SubTopic 10

-Section 50

-Paragraph 3

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=6382943&loc=d3e33918-111571

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

-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 18

-Paragraph 20

-Subparagraph a (1)

-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.

+ Details

Name:	us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The parent entity's interest in net assets of the subsidiary, expressed as a percentage.

+ References

No definition available.

+ Details

Name:	us-gaap_MinorityInterestOwnershipPercentageByParent
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant