Warranty Accruals Activity (Detail) - USD ($) $ in Thousands	12 Months Ended
	Aug. 31, 2017	Aug. 31, 2016	Aug. 31, 2015
Accrued maintenance
Balance at beginning of period	$ 18,646	$ 18,642	$ 14,329
Charged to cost of revenue	10,609	12,926	13,622
Payments	(11,588)	(12,922)	(9,309)
Balance at end of period	17,667	18,646	18,642
Accrued warranty
Balance at beginning of period	12,159	11,512	9,340
Charged to cost of revenue	6,872	6,069	7,206
Acquisition	3,526
Payments	(2,649)	(5,299)	(4,703)
Currency translation effect	829	(123)	(331)
Balance at end of period	$ 20,737	$ 12,159	$ 11,512