Business Combinations - Additional Information (Details)				3 Months Ended		12 Months Ended
	Oct. 17, 2025 USD ($)	Jul. 17, 2025 USD ($) $ / shares	Dec. 23, 2024 USD ($)	Oct. 31, 2024 USD ($) $ / shares	Apr. 30, 2022 USD ($)	Oct. 31, 2025 USD ($) $ / shares	Oct. 31, 2024 USD ($) $ / shares	Oct. 31, 2023 USD ($)
Business Combination [Line Items]
Common stock, par value (in USD per share) | $ / shares		$ 0.01		$ 0.01		$ 0.01	$ 0.01
Pre-tax gain on sale						$ 548,906,000	$ 0	$ 0
Net pre-tax gain on sale						508,044,000	868,830,000	0
Pro forma net income (loss)						743,822,000	651,499,000
Goodwill				$ 3,448,850,000		26,899,215,000	3,448,850,000	3,346,065,000
Payments to noncontrolling interests						30,000,000	0	0
Impairment of intangible assets				53,500,000			53,500,000
Redeemable non-controlling interest				$ 30,000,000		0	30,000,000
Acquisition-related costs						267,100,000	$ 161,800,000	13,800,000
OpenLight Photonics, Inc
Business Combination [Line Items]
Ownership percentage			95.00%	71.00%			71.00%
Payments to noncontrolling interests			$ 30,000,000
Disposal Group Sale, Not Discontinued Operations | Regulatory Divestitures
Business Combination [Line Items]
Sale consideration	$ 604,000,000.0
Net assets	55,100,000
Goodwill	19,500,000
Pre-tax gain on sale	548,900,000
Divestiture-related expenses	32,600,000
Net pre-tax gain on sale	$ 516,300,000
Ansys, Inc
Business Combination [Line Items]
Business acquisition, exchange ratio		0.3399
Business acquisition, share price (in USD per share) | $ / shares		$ 199.91
Total purchase consideration		$ 34,858,480,000
Payment to acquire business		17,613,185,000
Fair value of Synopsys Common Stock issued for outstanding Ansys Common Stock		17,100,000,000
Goodwill, expected tax deductible amount		0
Goodwill		$ 23,442,889,000
Ansys, Inc | Transaction costs
Business Combination [Line Items]
Pro forma net income (loss)							$ (298,400,000)
Ansys, Inc | Stock-based compensation costs
Business Combination [Line Items]
Pro forma net income (loss)							(71,500,000)
Ansys, Inc | Severance costs
Business Combination [Line Items]
Pro forma net income (loss)							(8,200,000)
Business Combination, Series of Individually Immaterial Business Combinations
Business Combination [Line Items]
Total purchase consideration							159,300,000	295,400,000
Goodwill, expected tax deductible amount				$ 0			0
Identifiable intangible assets				78,900,000			78,900,000	95,800,000
Goodwill				96,100,000			96,100,000
Net tangible liabilities				15,700,000			15,700,000	29,800,000
Business Combination, Series of Individually Immaterial Business Combinations | Design Automation
Business Combination [Line Items]
Goodwill, expected tax deductible amount								5,700,000
Goodwill				61,800,000			61,800,000	229,400,000
Business Combination, Series of Individually Immaterial Business Combinations | Design IP
Business Combination [Line Items]
Goodwill				34,300,000			34,300,000
OpenLight
Business Combination [Line Items]
Payment to acquire business					$ 90,000,000
Percent of company acquired					75.00%
Redeemable noncontrolling interest, redemption value					$ 30,000,000
Redeemable noncontrolling interest, put option value					10,100,000
Consideration transferred including redeemable noncontrolling interest					$ 100,100,000
Net loss of acquiree						3,500,000	91,700,000	40,900,000
Net loss of acquiree attributable to redeemable non-controlling interest						$ 800,000	22,000,000	$ 10,000,000
Redeemable non-controlling interest				$ 30,000,000.0			$ 30,000,000.0
Ansys, Inc
Business Combination [Line Items]
Common stock, par value (in USD per share) | $ / shares		$ 0.01
Juniper Networks, Inc | OpenLight Photonics, Inc
Business Combination [Line Items]
Percent of equity interests held by non-controlling owner				24.00%	25.00%		24.00%