Intangible Assets and Goodwill - Components of Company's Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Finite Lived Intangible Assets [Line Items]
Net Balance	$ 64,495		$ 64,495		$ 72,196
Amortization expense	6,500	$ 6,000	12,900	$ 11,800
Franchise agreements
Finite Lived Intangible Assets [Line Items]
Initial Cost	180,867		180,867		180,867
Accumulated Amortization	(116,372)		(116,372)		(108,671)
Net Balance	64,495		$ 64,495		72,196
Franchise agreements | Weighted Average
Finite Lived Intangible Assets [Line Items]
Useful life of intangible assets			12 years 7 months 6 days
Other intangible assets
Finite Lived Intangible Assets [Line Items]
Initial Cost	57,641		$ 57,641		54,704
Accumulated Amortization	(31,226)		(31,226)		(24,735)
Net Balance	26,415		$ 26,415		29,969
Other intangible assets | Weighted Average
Finite Lived Intangible Assets [Line Items]
Useful life of intangible assets			4 years 7 months 6 days
Software
Finite Lived Intangible Assets [Line Items]
Initial Cost	47,301		$ 47,301		44,389
Accumulated Amortization	(24,327)		(24,327)		(18,926)
Net Balance	22,974		$ 22,974		25,463
Software | Weighted Average
Finite Lived Intangible Assets [Line Items]
Useful life of intangible assets			4 years 4 months 24 days
Software Development
Finite Lived Intangible Assets [Line Items]
Capitalized software development costs	2,200		$ 2,200		1,400
Trademarks
Finite Lived Intangible Assets [Line Items]
Initial Cost	2,350		2,350		2,325
Accumulated Amortization	(1,406)		(1,406)		(1,274)
Net Balance	944		$ 944		1,051
Trademarks | Weighted Average
Finite Lived Intangible Assets [Line Items]
Useful life of intangible assets			8 years 4 months 24 days
Non-compete agreements
Finite Lived Intangible Assets [Line Items]
Initial Cost	3,920		$ 3,920		3,920
Accumulated Amortization	(3,339)		(3,339)		(2,814)
Net Balance	581		$ 581		1,106
Non-compete agreements | Weighted Average
Finite Lived Intangible Assets [Line Items]
Useful life of intangible assets			5 years 1 month 6 days
Training materials
Finite Lived Intangible Assets [Line Items]
Initial Cost	2,400		$ 2,400		2,400
Accumulated Amortization	(1,360)		(1,360)		(1,120)
Net Balance	1,040		$ 1,040		1,280
Training materials | Weighted Average
Finite Lived Intangible Assets [Line Items]
Useful life of intangible assets			5 years
Other
Finite Lived Intangible Assets [Line Items]
Initial Cost	1,670		$ 1,670		1,670
Accumulated Amortization	(794)		(794)		(601)
Net Balance	$ 876		$ 876		$ 1,069
Other | Weighted Average
Finite Lived Intangible Assets [Line Items]
Useful life of intangible assets			5 years 3 months 18 days