Leases - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Feb. 28, 2023	Feb. 28, 2022	Feb. 28, 2023	Feb. 28, 2022	Aug. 31, 2022
Lessor and Lessee, Lease, Description [Line Items]
Finance lease option to extend			options to extend up to 15 years
Car Hire Utilization Arrangements
Lessor and Lessee, Lease, Description [Line Items]
Operating lease rental revenues	$ 4.9	$ 3.9	$ 9.7	$ 8.5
Leasing & Management Services
Lessor and Lessee, Lease, Description [Line Items]
Operating lease rental revenues	$ 23.8	$ 16.3	$ 43.4	$ 31.3
Operating Lease, Lease Income, Statement of Income or Comprehensive Income [Extensible Enumeration]	Revenue from Contract with Customer, Excluding Assessed Tax	Revenue from Contract with Customer, Excluding Assessed Tax	Revenue from Contract with Customer, Excluding Assessed Tax	Revenue from Contract with Customer, Excluding Assessed Tax
Minimum
Lessor and Lessee, Lease, Description [Line Items]
Sublease period			1 year
Financing lease remaining lease term			1 year
Maximum
Lessor and Lessee, Lease, Description [Line Items]
Sublease period			13 years
Financing lease remaining lease term			76 years
Equipment on Operating Lease
Lessor and Lessee, Lease, Description [Line Items]
Accumulated depreciation	$ 55.2		$ 55.2		$ 48.6
Depreciation expense	$ 6.8	$ 5.4	$ 12.8	$ 10.5