Commitments and Contingencies (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Equipment Loans [Member]
Loss Contingencies [Line Items]
Number of letters of credit issued	2
Letters of credit outstanding, amount	$ 0.4
Percent guarantee of unconsolidated affiliate debt	50.00%
Debt Service Reserve or Liquidity Reserve [Member]
Loss Contingencies [Line Items]
Letters of credit outstanding, amount	5.3
Percent guarantee of unconsolidated affiliate debt	50.00%
KCSM [Member]
Loss Contingencies [Line Items]
Total period of time for payments due under railroad Concession to Mexican government	50 years
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%
KCSM [Member] | Materials and Other Expense [Member]
Loss Contingencies [Line Items]
Concession duty expense	$ 3.4	$ 1.3
Panama Canal Railway Company [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