Condensed Consolidating Balance Sheets (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Assets:
Current assets	$ 818.3	$ 942.4
Investments	36.4	41.1
Investments in consolidated subsidiaries	0	0
Property and equipment (including concession assets), net	7,154.7	6,356.3
Other assets	81.6	95.6
Total assets	8,091.0	7,435.4
Liabilities and equity:
Current liabilities	898.8	730.6
Long-term debt	1,841.0	1,856.9
Deferred income taxes	1,156.3	1,044.6
Other liabilities	130.8	126.7
Stockholders’ equity	3,755.5	3,370.6
Noncontrolling interest	308.6	306.0
Total liabilities and equity	8,091.0	7,435.4
Parent [Member]
Assets:
Current assets	2.7	2.6
Investments	0	0
Investments in consolidated subsidiaries	2,616.0	2,154.6
Property and equipment (including concession assets), net	0	0.1
Other assets	1.6	1.5
Total assets	2,620.3	2,158.8
Liabilities and equity:
Current liabilities	(1,156.0)	(1,216.5)
Long-term debt	0.2	0.2
Deferred income taxes	7.3	(11.7)
Other liabilities	3.7	6.6
Stockholders’ equity	3,765.1	3,380.2
Noncontrolling interest	0	0
Total liabilities and equity	2,620.3	2,158.8
KCSR [Member]
Assets:
Current assets	281.7	403.0
Investments	3.9	9.6
Investments in consolidated subsidiaries	(4.3)	(2.1)
Property and equipment (including concession assets), net	3,385.5	2,780.4
Other assets	45.2	50.9
Total assets	3,712.0	3,241.8
Liabilities and equity:
Current liabilities	1,484.7	1,580.6
Long-term debt	701.0	704.3
Deferred income taxes	835.8	719.8
Other liabilities	94.4	92.0
Stockholders’ equity	596.1	145.1
Noncontrolling interest	0	0
Total liabilities and equity	3,712.0	3,241.8
Guarantor Subsidiaries [Member]
Assets:
Current assets	6.0	8.8
Investments	0	0
Investments in consolidated subsidiaries	471.3	461.8
Property and equipment (including concession assets), net	193.3	198.6
Other assets	0	0
Total assets	670.6	669.2
Liabilities and equity:
Current liabilities	115.6	130.7
Long-term debt	0.2	0.2
Deferred income taxes	132.0	127.6
Other liabilities	0.7	0.7
Stockholders’ equity	113.5	104.0
Noncontrolling interest	308.6	306.0
Total liabilities and equity	670.6	669.2
Non-Guarantor Subsidiaries [Member]
Assets:
Current assets	562.5	560.1
Investments	32.5	31.5
Investments in consolidated subsidiaries	0	0
Property and equipment (including concession assets), net	3,575.9	3,377.2
Other assets	34.8	43.2
Total assets	4,205.7	4,012.0
Liabilities and equity:
Current liabilities	489.1	267.9
Long-term debt	1,139.6	1,152.2
Deferred income taxes	181.2	208.9
Other liabilities	32.0	27.5
Stockholders’ equity	2,363.8	2,355.5
Noncontrolling interest	0	0
Total liabilities and equity	4,205.7	4,012.0
Consolidating Adjustments [Member]
Assets:
Current assets	(34.6)	(32.1)
Investments	0	0
Investments in consolidated subsidiaries	(3,083.0)	(2,614.3)
Property and equipment (including concession assets), net	0	0
Other assets	0	0
Total assets	(3,117.6)	(2,646.4)
Liabilities and equity:
Current liabilities	(34.6)	(32.1)
Long-term debt	0	0
Deferred income taxes	0	0
Other liabilities	0	(0.1)
Stockholders’ equity	(3,083.0)	(2,614.2)
Noncontrolling interest	0	0
Total liabilities and equity	$ (3,117.6)	$ (2,646.4)