Segments - Summary of Company's Assets by Reportable Segment (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Segment Reporting, Asset Reconciling Item [Line Items]
Revenue	$ 148,817	$ 121,333
Total consolidated assets	1,509,592		$ 1,353,416
Franchise revenue
Segment Reporting, Asset Reconciling Item [Line Items]
Revenue	65,762	54,612
Corporate-owned Stores
Segment Reporting, Asset Reconciling Item [Line Items]
Revenue	38,044	32,708
Equipment revenue
Segment Reporting, Asset Reconciling Item [Line Items]
Revenue	45,011	$ 34,013
Operating Segments | Franchise revenue
Segment Reporting, Asset Reconciling Item [Line Items]
Total consolidated assets	332,811		319,422
Operating Segments | Corporate-owned Stores
Segment Reporting, Asset Reconciling Item [Line Items]
Total consolidated assets	354,606		243,221
Operating Segments | Equipment revenue
Segment Reporting, Asset Reconciling Item [Line Items]
Total consolidated assets	201,705		210,462
Unallocated
Segment Reporting, Asset Reconciling Item [Line Items]
Total consolidated assets	$ 620,470		$ 580,311