Concession duty expense payable to the Mexican government.

No definition available.

Name:	ksu_ConcessionDutyExpense
Namespace Prefix:	ksu_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Percentage of gross revenue payable under railroad Concession to Mexican Government.

+ References

No definition available.

+ Details

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

- Definition

Percentage guarantee by the Company of an unconsolidated affiliate's reserves or additional loans.

+ References

No definition available.

+ Details

Name:	ksu_PercentGuaranteeOfUnconsolidatedAffiliateDebt
Namespace Prefix:	ksu_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(1))

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

+ Details

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

- Definition

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(2))

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

+ Details

Name:	us-gaap_DebtInstrumentMaturityDate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

Name:	us-gaap_LettersOfCreditOutstandingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_LossContingenciesLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	dei_LegalEntityAxis=ksu_KcsmMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=ksu_PanamaCanalRailwayCompanyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_GuaranteeObligationsByNatureAxis=us-gaap_FinancialGuaranteeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Commitments and Contingencies (Narrative) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Financial Guarantee [Member]
Loss Contingencies [Line Items]
Letters of credit outstanding, amount	$ 5.4
Percent guarantee of unconsolidated affiliate debt	50.00%
KCSM [Member]
Loss Contingencies [Line Items]
Percentage of gross revenue payable under railroad Concession to Mexican government	1.25%
KCSM [Member] \| Materials and Other Expense [Member]
Loss Contingencies [Line Items]
Concession duty expense	$ 15.8	$ 14.3	$ 9.4
Panama Canal Railway Company [Member] \| Financial Guarantee [Member] \| 7.0% Senior Secured Notes due November 1, 2026 [Member]
Loss Contingencies [Line Items]
Debt instrument, stated interest rate	7.00%
Debt instrument, maturity date	Nov. 01, 2026