Intangible Franchise Rights and Goodwill - Roll-Forward of Goodwill by Reportable Segment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Goodwill [Roll Forward]
BALANCE	$ 963.9	$ 913.0
Additions through acquisitions	43.3	72.5
Disposals	(1.6)	(13.4)
Currency translation	2.7	(8.2)
BALANCE	1,008.3	963.9
Accumulated impairment	97.8	97.8	$ 97.8
U.S.
Goodwill [Roll Forward]
BALANCE	861.6	835.3
Additions through acquisitions	42.0	39.7
Disposals	(1.3)	(13.4)
Currency translation	0.0	0.0
BALANCE	902.3	861.6
U.K.
Goodwill [Roll Forward]
BALANCE	87.6	65.0
Additions through acquisitions	1.3	28.5
Disposals	0.0	0.0
Currency translation	3.2	(5.9)
BALANCE	92.1	87.6
Brazil
Goodwill [Roll Forward]
BALANCE	14.7	12.7
Additions through acquisitions	0.0	4.3
Disposals	(0.3)	0.0
Currency translation	(0.5)	(2.3)
BALANCE	$ 13.9	$ 14.7