Elimination of Deferred Statutory Profit Sharing Liability, Net (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended			3 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jun. 30, 2012
Restructuring and Related Activities [Line Items]
Net reduction to operating expense as a result of the organizational restructuring	$ 0	$ 0	$ 43.0
Elimination of deferred Mexican statutory profit sharing liability	0	0	47.8
KCSM [Member] | Organizational Restructuring [Member]
Restructuring and Related Activities [Line Items]
Net reduction to operating expense as a result of the organizational restructuring				43.0
Elimination of deferred Mexican statutory profit sharing liability				47.8
Transaction costs of organizational restructuring				$ 4.8