Franchise Operating Rights & Goodwill - Franchise Operating Rights and Goodwill (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Franchise operating rights
Balance at the beginning of the period	$ 620.1	$ 634.1
Impairment		(14.0)	$ (9.7)
Balance at the end of the period	620.1	620.1	634.1
Goodwill
Balance at the beginning of the period	225.1	225.1
Impairment	0.0	0.0	0.0
Balance at the end of the period	225.1	225.1	225.1
Franchise operating rights and goodwill
Balance at the beginning of the period	845.2	859.2
Impairment		(14.0)	(9.7)
Balance at the end of the period	$ 845.2	$ 845.2	$ 859.2