Other Intangible Assets - Schedule of Finite-lived Intangible Assets (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Gross	$ 211.7	$ 215.8
Accumulated Amortization	(133.7)	(122.9)
Net	78.0	92.9
Franchising rights
Finite-Lived Intangible Assets [Line Items]
Gross	200.0	200.0
Accumulated Amortization	(131.0)	(121.0)
Net	69.0	79.0
Reacquired Franchise Rights
Finite-Lived Intangible Assets [Line Items]
Gross	8.3	11.6
Accumulated Amortization	(2.6)	(1.8)
Net	5.7	9.8
Favorable leaseholds
Finite-Lived Intangible Assets [Line Items]
Gross	3.4	4.2
Accumulated Amortization	(0.2)	(0.1)
Net	$ 3.2	$ 4.1