Geographic Information (Information by Geographic Area) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ 642.5	$ 677.5	$ 649.7	$ 607.4	$ 615.6	$ 621.6	$ 579.3	$ 552.8	$ 2,577.1	$ 2,369.3	$ 2,238.6
Property and equipment (including concession assets), net	7,154.7				6,356.3				7,154.7	6,356.3
UNITED STATES
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									1,372.2	1,268.0	1,216.7
Property and equipment (including concession assets), net	4,311.0				3,662.2				4,311.0	3,662.2
MEXICO
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									1,204.9	1,101.3	1,021.9
Property and equipment (including concession assets), net	$ 2,843.7				$ 2,694.1				$ 2,843.7	$ 2,694.1