Accounts Payable and Accrued Liabilities (Detail) - Entity [Domain] - USD ($) $ in Thousands	May. 31, 2015	Feb. 28, 2015	Aug. 31, 2014	May. 31, 2014	Feb. 28, 2014	Aug. 31, 2013
Accounts Payable and Accrued Liabilities [Line Items]
Trade payables	$ 251,634		$ 204,744
Other accrued liabilities	64,189		66,421
Accrued payroll and related liabilities	57,839		64,959
Accrued maintenance	17,965		14,329
Accrued warranty	10,198	$ 9,188	9,340	$ 9,718	$ 10,673	$ 12,128
Income taxes payable	163		19,709
Other	3,556		3,787
Accounts payable and accrued liabilities	$ 405,544		$ 383,289