Quarterly Financial Data (Unaudited) (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended										12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012		Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011		Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Quarterly Financial Data [Abstract]
Revenues	$ 568.4	$ 577.4	$ 545.3		$ 547.5	$ 530.3	$ 544.5		$ 534.9	$ 488.6	$ 2,238.6	$ 2,098.3	$ 1,814.8
Operating income	173.6	180.7	203.8	[1]	157.8	150.4	181.8	[2]	151.6	127.8	715.9	611.6	486.5
Net income	92.5	90.7	120.9		75.3	96.0	100.1		71.7	64.1	379.4	331.9	180.0
Net income attributable to Kansas City Southern and subsidiaries	91.8	90.1	120.4		75.0	95.7	99.8		70.8	64.0	377.3	330.3	180.2
Per share data:
Basic earnings per common share	$ 0.84	$ 0.82	$ 1.10		$ 0.68	$ 0.87	$ 0.91		$ 0.65	$ 0.60	$ 3.44	$ 3.04	$ 1.69
Diluted earnings per common share	$ 0.83	$ 0.82	$ 1.09		$ 0.68	$ 0.87	$ 0.91		$ 0.64	$ 0.58	$ 3.43	$ 3.00	$ 1.67
Elimination of deferred statutory profit sharing liability, net			43.0								43.0	0	0
Gain on insurance recoveries related to hurricane damage							$ 25.6				$ 0	$ 25.6	$ 0

[1] During the second quarter of 2012, the Company recognized a pre-tax gain of $43.0 million within operating expenses for the elimination of deferred statutory profit sharing liability, net as a result of the organizational restructuring during the period.

[2] During the third quarter of 2011, the Company recognized a pre-tax gain of $25.6 million within operating expenses for insurance recoveries related to hurricane damage.