Equipment on Operating Leases, Net - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Aug. 31, 2017	Aug. 31, 2016	Aug. 31, 2015
Property, Plant and Equipment [Line Items]
Accumulated depreciation	$ 322,008	$ 282,556
Depreciation expense	45,500	39,200	$ 31,400
Revenue associated with equipment hiring arrangements	13,000	14,700	20,200
Property Subject to Operating Lease
Property, Plant and Equipment [Line Items]
Accumulated depreciation	91,100	92,600
Depreciation expense	$ 12,100	$ 16,600	$ 9,400