Financial Information from Continuing Operations By Geographic Region (Detail) - USD ($) $ in Thousands	12 Months Ended
	Aug. 31, 2018	Aug. 31, 2017	Aug. 31, 2016
Geographic Reporting Disclosure [Line Items]
Percentage Of Export Sales From Domestic To Total Net Sales	7.00%
Assets	$ 1,481,338	$ 1,516,955
Net sales	1,182,611	1,095,784	$ 1,149,410
Long-Lived Assets	101,735	98,334
United States
Geographic Reporting Disclosure [Line Items]
Net sales	509,952	480,801	477,670
Long-Lived Assets	42,563	36,254
Netherlands
Geographic Reporting Disclosure [Line Items]
Net sales	166,542	130,724	143,517
Long-Lived Assets	12,200	9,134
FRANCE
Geographic Reporting Disclosure [Line Items]
Net sales	40,351	39,563	42,780
AUSTRALIA
Geographic Reporting Disclosure [Line Items]
Net sales	28,510	38,924	62,779
UNITED KINGDOM
Geographic Reporting Disclosure [Line Items]
Net sales	87,182	84,106	115,183
Long-Lived Assets	4,076	5,467
China
Geographic Reporting Disclosure [Line Items]
Net sales	64,031	68,373	47,312
Long-Lived Assets	14,909	16,332
SWEDEN
Geographic Reporting Disclosure [Line Items]
Net sales	50,517	37,813	35,424
UNITED ARAB EMIRATES
Geographic Reporting Disclosure [Line Items]
Net sales	43,707	39,974	55,906
Long-Lived Assets	7,876	8,451
All other
Geographic Reporting Disclosure [Line Items]
Net sales	191,819	175,506	$ 168,839
Long-Lived Assets	20,111	22,696
General Corporate
Geographic Reporting Disclosure [Line Items]
Assets	$ 234,036	$ 204,551