Geographic Information (Information by Geographic Area) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ 656.4	$ 568.5	$ 1,265.9	$ 1,131.2
Property and equipment (including concession assets), net	8,247.3		8,247.3		$ 8,069.7
UNITED STATES
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	344.4	286.8	665.6	579.1
Property and equipment (including concession assets), net	5,118.0		5,118.0		4,960.6
MEXICO
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	312.0	$ 281.7	600.3	$ 552.1
Property and equipment (including concession assets), net	$ 3,129.3		$ 3,129.3		$ 3,109.1