Corporate-Owned and Franchisee-Owned Stores - Schedule of Changes in Corporate-owned and Franchisee-owned Stores (Detail) - store	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Number Of Stores [Roll Forward]
Stores operated at beginning of period	2,001	1,742
New stores opened	39	65
Stores acquired, debranded, sold or consolidated	(1)	(1)
Stores operated at end of period	2,039	1,806
Franchisee-Owned Stores
Number Of Stores [Roll Forward]
Stores operated at beginning of period	1,903	1,666
New stores opened	38	65
Stores acquired, debranded, sold or consolidated	(1)	(1)
Stores operated at end of period	1,940	1,730
Corporate-Owned Stores
Number Of Stores [Roll Forward]
Stores operated at beginning of period	98	76
New stores opened	1	0
Stores acquired from franchisees	0	0
Stores operated at end of period	99	76