Fair Value Measurements - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($) item	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Percentage of gross revenues to be paid yearly	8.00%
Annual payment period	120 days
Deferred revenue, current and noncurrent	$ (1,566)	$ 228	$ 4,705
Measured on a recurring basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration liability	5,005	5,070
Level 3 | Measured on a recurring basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration liability	5,005	$ 5,070	$ 6,580
Ten Percent Reduction In Franchise Sales [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Deferred revenue, current and noncurrent	300
One Percent Change To Discount Rate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Deferred revenue, current and noncurrent	$ 200
Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assumed number of franchises sold annually | item	50
Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assumed number of franchises sold annually | item	80