Refranchising Initiative (Narrative) (Details) - franchise	3 Months Ended		9 Months Ended	12 Months Ended
	May 31, 2017	Nov. 30, 2016	May 31, 2017	Aug. 31, 2016	Jun. 30, 2016
Franchisor Disclosure [Line Items]
Franchise restaurant ownership target					95.00%
Refranchised Company Drive-Ins				38
Refranchising Initiative 2017 [Member]
Franchisor Disclosure [Line Items]
Refranchised Company Drive-Ins	0	53	110
Refranchising Initiative 2017 [Member] | Non-controlling operating interest [Member]
Franchisor Disclosure [Line Items]
Refranchised Company Drive-Ins			106
Refranchising Initiative 2016 [Member]
Franchisor Disclosure [Line Items]
Refranchised Company Drive-Ins				29
Refranchising Initiative 2016 [Member] | Non-controlling operating interest [Member]
Franchisor Disclosure [Line Items]
Refranchised Company Drive-Ins				25