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

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

+ References

No definition available.

+ Details

Name:	ksu_DurationOfPaymentsDueUnderRailroadConcessionToMexicanGovernment
Namespace Prefix:	ksu_
Data Type:	xbrli:durationItemType
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

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

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

+ 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 210.5-02.22(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 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

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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

- Details

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

- Details

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

- Details

Name:	us-gaap_IncomeStatementLocationAxis=ksu_MaterialsAndOtherExpenseMember
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_DebtInstrumentAxis=ksu_SevenPointZeroPercentSeniorSecuredNotesDueNovember2026Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Commitments and Contingencies (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Financial Guarantee [Member]
Loss Contingencies [Line Items]
Letter of credit outstanding, amount	$ 5.5		$ 5.5
Percent guarantee of unconsolidated affiliate debt	50.00%		50.00%
KCSM [Member]
Loss Contingencies [Line Items]
Total period of time for payments due under railroad Concession to Mexican government			50 years
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	$ 4.3	$ 3.7	$ 8.5	$ 7.3
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%		7.00%
Debt instrument, maturity date			Nov. 01, 2026