Condensed Consolidated Statements of Comprehensive Income (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Apr. 30, 2019	Apr. 30, 2018	Apr. 30, 2019	Apr. 30, 2018
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 91,923	$ 91,235	$ 140,490	$ 195,790
Components of other comprehensive income:
Foreign currency translation adjustments	(9,064)	(19,284)	7,399	19,298
Amortization of prior service cost and net actuarial losses, net of tax	1,598	2,812	2,950	4,321
Total other comprehensive income (loss)	(7,466)	(16,472)	10,349	23,619
Total comprehensive income	$ 84,457	$ 74,763	$ 150,839	$ 219,409