Net Income per Share - Reconciliation of Weighted Average Common Shares Used to Calculate Basic Net Income Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Jan. 31, 2022	Jan. 31, 2021
Numerator:
Net income attributed to Synopsys	$ 313,687	$ 162,345
Denominator:
Weighted-average common shares for basic net income per share (shares)	153,218	152,498
Dilutive effect of potential common shares from equity-based compensation (shares)	4,055	4,779
Weighted-average common shares for diluted net income per share (shares)	157,273	157,277
Net income per share attributed to Synopsys:
Basic (in USD per share)	$ 2.05	$ 1.06
Diluted (in USD per share)	$ 1.99	$ 1.03
Anti-dilutive employee stock-based awards excluded (shares)	170	334