Geographic Information (Information by Geographic Area) (Details) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020 USD ($)	Sep. 30, 2020 USD ($)	Jun. 30, 2020 USD ($)	Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2020 USD ($) Segments	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Revenues from External Customers and Long-Lived Assets [Line Items]
Number of reportable business segments of the Company | Segments									1
Revenues	$ 693.4	$ 659.6	$ 547.9	$ 731.7	$ 729.5	$ 747.7	$ 714.0	$ 674.8	$ 2,632.6	$ 2,866.0	$ 2,714.0
Property and equipment (including concession assets), net	8,997.8				8,806.3				8,997.8	8,806.3
UNITED STATES
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									1,388.5	1,493.5	1,424.8
Property and equipment (including concession assets), net	5,594.6				5,435.9				5,594.6	5,435.9
MEXICO
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									1,244.1	1,372.5	$ 1,289.2
Property and equipment (including concession assets), net	$ 3,403.2				$ 3,370.4				$ 3,403.2	$ 3,370.4