Summary of Significant Accounting Policies - Goodwill and Other Intangible Assets (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Goodwill [Line Items]
Goodwill	$ 1,297,100,000	$ 1,343,000,000	$ 1,239,900,000
Finite-lived:
Gross	463,300,000	472,900,000
Accumulated Amortization	367,700,000	339,900,000
Net	95,600,000	133,000,000
Indefinite-lived:
Gross	150,700,000	151,000,000
Net	150,700,000	151,000,000
Total intangible assets
Gross	614,000,000	623,900,000
Accumulated Amortization	367,700,000	339,900,000
Net	246,300,000	284,000,000
Goodwill, accumulated impairment loss	513,400,000	513,400,000	513,400,000
Amortization expense related to intangibles	35,100,000	34,600,000	36,000,000
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2019	29,000,000
2020	24,200,000
2021	13,400,000
2022	9,900,000
2023	7,700,000
Impairment of goodwill	$ 0	0	$ 0
Income approach weight for goodwill impairment for certain reporting units	75.00%
Market approach weight for goodwill impairment for certain reporting units	25.00%
Minimum
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Discount rate for goodwill impairment test (as a percent)	10.60%
Maximum
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Discount rate for goodwill impairment test (as a percent)	14.20%
Tradenames
Indefinite-lived:
Gross	$ 52,000,000	52,000,000
Net	52,000,000	52,000,000
Total intangible assets
Trademarks, accumulated impairment loss	139,500,000	139,500,000
Reacquired franchise rights
Indefinite-lived:
Gross	98,700,000	99,000,000
Net	98,700,000	99,000,000
Customer relationships
Finite-lived:
Gross	444,800,000	453,600,000
Accumulated Amortization	351,700,000	325,200,000
Net	$ 93,100,000	128,400,000
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Weighted-average useful lives	13 years
Other
Finite-lived:
Gross	$ 18,500,000	19,300,000
Accumulated Amortization	16,000,000	14,700,000
Net	$ 2,500,000	$ 4,600,000
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Weighted-average useful lives	4 years