Employee Benefit Plans - Restricted Stock Units (Detail) - Restricted Stock Units - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		12 Months Ended
		Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2018		Oct. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Beginning balance (in shares)		3,857	3,769	3,843
Granted (in shares)		2,041	1,844	1,679	[1]
Vested (in shares)	[2]	(1,480)	(1,508)	(1,495)
Forfeited (in shares)		(288)	(248)	(258)
Ending balance (in shares)		4,130	3,857	3,769		3,843
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted Average Grant Date Fair Value, Beginning balance (in USD per share)		$ 97.21	$ 72.75	$ 57.26
Granted (in USD per share)		168.15	119.27	89.35
Vested (in USD per share)		88.70	65.97	52.55
Forfeited (in USD per share)		104.67	79.49	67.04
Weighted Average Grant Date Fair Value, Ending balance (in USD per share)		$ 134.80	$ 97.21	$ 72.75		$ 57.26
Weighted Average Remaining Contractual Life (In Years)		1 year 5 months 19 days	1 year 6 months 21 days	1 year 5 months 15 days		1 year 6 months 14 days
Aggregate Fair Value		$ 261,563	$ 176,659	$ 136,417

[1] The Company assumed unvested restricted stock units from acquisitions including Black Duck.

[2] The number of vested restricted stock units includes shares that were withheld on behalf of employees to satisfy the minimum statutory tax withholding requirements.