Equipment on Operating Leases, Net - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Aug. 31, 2018	Aug. 31, 2017	Aug. 31, 2016
Property, Plant and Equipment [Line Items]
Accumulated depreciation	$ 361,932	$ 322,008
Depreciation expense	54,500	45,500	$ 39,200
Revenue associated with equipment hiring arrangements	12,800	13,000	14,700
Property Subject to Operating Lease
Property, Plant and Equipment [Line Items]
Accumulated depreciation	64,900	91,100
Depreciation expense	$ 11,200	$ 12,100	$ 16,600