Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Oct. 31, 2019	Jul. 31, 2019	Apr. 30, 2019	Jan. 31, 2019	Oct. 31, 2018	Jul. 31, 2018	Apr. 30, 2018	Jan. 31, 2018	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2017
Earnings Per Share [Abstract]
Net income	$ (22,871)	$ 53,362	$ 40,636	$ (17,833)	$ (43,198)	$ 11,475	$ 41,948	$ 51,206	$ 53,294	$ 61,431	$ 279,745
Distributed and undistributed (earnings) to unvested restricted stock									(778)	(878)	(4,285)
Distributed and undistributed earnings to common shareholders — Basic									$ 52,516	$ 60,553	$ 275,460
Weighted average shares outstanding — Basic									21,829	22,429	22,393
Weighted average shares outstanding — Diluted									21,829	22,429	22,393
Earnings per common share - Basic (in usd per share)									$ 2.41	$ 2.70	$ 12.30
Earnings per common share - Diluted (in usd per share)	$ (1.05)	$ 2.41	$ 1.83	$ (0.82)	$ (1.95)	$ 0.50	$ 1.84	$ 2.24	$ 2.41	$ 2.70	$ 12.30