Intangible Assets and Goodwill - Components of Company's Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Finite Lived Intangible Assets [Line Items]
Net Balance	$ 68,337		$ 72,196
Net Balance	28,284		29,969
Amortization expense	6,400	$ 5,900
Franchise agreements
Finite Lived Intangible Assets [Line Items]
Initial Cost	180,867	180,867
Accumulated Amortization	(112,530)	(108,671)
Net Balance	$ 68,337	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	$ 56,191	54,704
Accumulated Amortization	(27,907)	(24,735)
Net Balance	$ 28,284	29,969
Other intangible assets | Weighted Average
Finite Lived Intangible Assets [Line Items]
Useful life of intangible assets	4 years 8 months 12 days
Software
Finite Lived Intangible Assets [Line Items]
Initial Cost	$ 45,876	44,389
Accumulated Amortization	(21,519)	(18,926)
Net Balance	$ 24,357	25,463
Software | Weighted Average
Finite Lived Intangible Assets [Line Items]
Useful life of intangible assets	4 years 6 months
Trademarks
Finite Lived Intangible Assets [Line Items]
Initial Cost	$ 2,325	2,325
Accumulated Amortization	(1,341)	(1,274)
Net Balance	$ 984	1,051
Trademarks | Weighted Average
Finite Lived Intangible Assets [Line Items]
Useful life of intangible assets	8 years 3 months 18 days
Software Development
Finite Lived Intangible Assets [Line Items]
Capitalized software development costs	$ 1,600		$ 1,400
Non-compete agreements
Finite Lived Intangible Assets [Line Items]
Initial Cost	3,920	3,920
Accumulated Amortization	(3,110)	(2,814)
Net Balance	$ 810	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
Accumulated Amortization	(1,240)	(1,120)
Net Balance	$ 1,160	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
Accumulated Amortization	(697)	(601)
Net Balance	$ 973	$ 1,069
Other | Weighted Average
Finite Lived Intangible Assets [Line Items]
Useful life of intangible assets	5 years 3 months 18 days