Income Taxes - Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Jul. 31, 2018	Oct. 31, 2018	Oct. 31, 2017	Oct. 31, 2016
Income Tax Disclosure [Abstract]
Balance at beginning of year		$ 3,781	$ 3,336	$ 6,258
Additions based on tax positions related to the current year		310	529	522
Additions for tax positions of prior years		40	621	310
Reductions for tax positions of prior years		(120)	(150)	(140)
Settlements				(3,091)
Lapse of statute of limitations	$ (1,041)	(1,120)	(555)	(523)
Balance at end of year		$ 2,891	$ 3,781	$ 3,336