Impairment and Closure Charges - Changes in the carrying amount of intangible assets (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2020 USD ($)
Finite-lived Intangible Assets [Roll Forward]
Amortization expense	$ (8,300)
Finite And Indefinite Lived Intangible Assets [Roll Forward]
Intangible assets balance, beginning	575,103
Impairment loss	(14,300)
Intangible assets balance, end	552,943
Not Subject to Amortization
Indefinite-lived Intangible Assets [Roll Forward]
Additions	400
Franchise Rights | Subject to Amortization
Finite-lived Intangible Assets [Roll Forward]
Finite-lived intangible assets, balance, beginning	79,000
Amortization expense	(7,500)
Finite-lived intangible assets, balance, end	71,500
Reacquired Franchise Rights | Subject to Amortization
Finite-lived Intangible Assets [Roll Forward]
Finite-lived intangible assets, balance, beginning	9,800
Impairment loss	(3,300)
Amortization expense	(700)
Finite-lived intangible assets, balance, end	5,800
Leasehold Improvements | Subject to Amortization
Finite-lived Intangible Assets [Roll Forward]
Finite-lived intangible assets, balance, beginning	4,100
Amortization expense	(100)
Finite-lived intangible assets, balance, end	4,000
Trade Names
Indefinite-lived Intangible Assets [Roll Forward]
Impairment	(11,000)
Trade Names | Not Subject to Amortization
Indefinite-lived Intangible Assets [Roll Forward]
Indefinite-lived intangible assets balance, beginning	479,000
Impairment	(11,000)
Indefinite-lived intangible assets balance, end	468,000
Other Intangible Assets | Not Subject to Amortization
Indefinite-lived Intangible Assets [Roll Forward]
Indefinite-lived intangible assets balance, beginning	3,200
Indefinite-lived intangible assets balance, end	$ 3,600