Segments - Summary of Company's Assets by Reportable Segment (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
Segment Reporting, Asset Reconciling Item [Line Items]
Total consolidated assets	$ 1,353,416	$ 1,095,750	$ 1,092,465
Operating segments | Franchise revenue
Segment Reporting, Asset Reconciling Item [Line Items]
Total consolidated assets	319,422		243,348
Operating segments | Corporate-owned stores
Segment Reporting, Asset Reconciling Item [Line Items]
Total consolidated assets	243,221		167,367
Operating segments | Equipment revenue
Segment Reporting, Asset Reconciling Item [Line Items]
Total consolidated assets	210,462		206,632
Unallocated
Segment Reporting, Asset Reconciling Item [Line Items]
Total consolidated assets	$ 580,311		$ 475,118