Accounts Payable and Accrued Liabilities - Accounts Payable and Accrued Liabilities (Detail) - USD ($) $ in Thousands	Aug. 31, 2018	Aug. 31, 2017	Aug. 31, 2016	Aug. 31, 2015
Accounts Payable and Accrued Liabilities [Line Items]
Trade payables	$ 226,405	$ 180,592
Other accrued liabilities	73,273	107,002
Accrued payroll and related liabilities	105,111	84,749
Accrued warranty	27,395	20,737	$ 12,159	$ 11,512
Accrued maintenance	9,090	17,667	$ 18,646	$ 18,642
Income taxes payable	4,771
Other	3,812	4,314
Accounts payable and accrued liabilities	$ 449,857	$ 415,061