Quarterly Financial Data (unaudited) (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								9 Months Ended	12 Months Ended
	Oct. 31, 2017	Jul. 31, 2017	Apr. 30, 2017	Jan. 31, 2017	Oct. 31, 2016	Jul. 31, 2016	Apr. 30, 2016	Jan. 31, 2016	Jul. 31, 2017	Oct. 31, 2017	Oct. 31, 2016	Oct. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Net sales	$ 919,941	$ 931,901	$ 802,038	$ 688,346	$ 790,811	$ 727,991	$ 692,089	$ 605,166		$ 3,342,226	$ 2,816,057	$ 2,803,480
Gross profit	173,516	239,316	146,755	81,955	160,655	129,428	113,813	50,105
Net income	$ 72,871	$ 115,834	$ 67,015	$ 24,025	$ 75,962	$ 54,716	$ 47,602	$ 10,681		$ 279,745	$ 188,961	$ 216,001
Diluted (in usd per share)	$ 3.20	$ 5.09	$ 2.95	$ 1.06	$ 3.36	$ 2.42	$ 2.11	$ 0.47		$ 12.30	$ 8.37	$ 9.52
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reduction of income tax expense			$ 72	$ 852					$ 952	$ 3,345	$ 0	$ 0
Accounting Standards Update 2016-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Earnings per share (in usd per share)			$ 0.01	$ 0.04