Restaurant Information by Ownership Type (Detail) - Restaurant	Sep. 30, 2016	Sep. 30, 2015
Segment Reporting Information [Line Items]
Number of Restaurants	36,615	36,405
Franchised
Segment Reporting Information [Line Items]
Number of Restaurants	30,559	29,851
Franchised | Conventional franchised
Segment Reporting Information [Line Items]
Number of Restaurants	21,456	21,009
Franchised | Developmental licensed
Segment Reporting Information [Line Items]
Number of Restaurants	5,742	5,348
Franchised | Affiliated
Segment Reporting Information [Line Items]
Number of Restaurants	3,361	3,494
Company-operated
Segment Reporting Information [Line Items]
Number of Restaurants	6,056	6,554