Leases - average lease terms and discount rates (Details)	Aug. 31, 2023	Aug. 31, 2022
Weighted average remaining lease term in years
Operating leases	9 years 7 months 6 days	10 years
Finance leases	17 years 4 months 24 days	19 years
Weighted average discount rate
Operating leases	5.35%	4.83%
Finance leases	5.25%	5.19%