Net Income (Loss) Per Share - Schedule of Reconciliation of Weighted-Average Common Shares Used to Calculate Net Income (Loss) Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Oct. 31, 2025	Oct. 31, 2024	Oct. 31, 2023
Numerator:
Net income from continuing operations attributed to Synopsys	$ 1,336,120	$ 1,441,710	$ 1,227,045
Net income (loss) from discontinued operations attributed to Synopsys	(3,900)	821,670	2,843
Net income attributed to Synopsys	$ 1,332,220	$ 2,263,380	$ 1,229,888
Denominator:
Weighted average common shares for basic net income per share (in shares)	163,947	153,138	152,146
Dilutive effect of common share equivalents from equity-based compensation (in shares)	1,709	2,806	3,049
Weighted average common shares for diluted net income per share (in shares)	165,656	155,944	155,195
Net income (loss) per share attributed to Synopsys - basic:
Continuing operations (in USD per share)	$ 8.15	$ 9.41	$ 8.06
Discontinued operations (in USD per share)	(0.02)	5.37	0.02
Basic net income per share (in USD per share)	8.13	14.78	8.08
Net income (loss) per share attributed to Synopsys - diluted:
Continuing operations (in USD per share)	8.07	9.25	7.91
Discontinued operations (in USD per share)	(0.03)	5.26	0.01
Diluted net income per share (in USD per share)	$ 8.04	$ 14.51	$ 7.92
Anti-dilutive employee stock-based awards excluded (shares)	427	229	475