Quarterly Financial Data (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Aug. 31, 2018	May 31, 2018	Feb. 28, 2018	Nov. 30, 2017	Aug. 31, 2017	May 31, 2017	Feb. 28, 2017	Nov. 30, 2016	Aug. 31, 2018	Aug. 31, 2017	Aug. 31, 2016
Quarterly Financial Information Disclosure [Line Items]
Net sales									$ 1,182,611	$ 1,095,784	$ 1,149,410
Gross profit									415,260	379,717	403,397
Net (loss) earnings									$ (21,648)	$ (66,213)	$ (105,174)
Net earnings (loss) per share:
Basic (in dollars per share)									$ (0.36)	$ (1.11)	$ (1.78)
Diluted (in dollars per share)									$ (0.36)	$ (1.11)	$ (1.78)
Quarterly unaudited data [Member]
Quarterly Financial Information Disclosure [Line Items]
Net sales	$ 301,395	$ 317,096	$ 275,165	$ 288,955	$ 275,695	$ 295,427	$ 258,869	$ 265,793
Gross profit	108,144	116,509	89,696	100,911	96,519	102,804	87,327	93,067
Net (loss) earnings	$ (37,665)	$ 29,012	$ (18,221)	$ 5,226	$ (98,764)	$ 22,511	$ 5,074	$ 4,966
Net earnings (loss) per share:
Basic (in dollars per share)	$ (0.62)	$ 0.48	$ (0.30)	$ 0.09	$ (1.65)	$ 0.38	$ 0.09	$ 0.08
Diluted (in dollars per share)	$ (0.62)	$ 0.48	$ (0.30)	$ 0.09	$ (1.65)	$ 0.37	$ 0.08	$ 0.08