Unaudited Condensed Consolidated Statements of Stockholders' Equity Statement - USD ($) shares in Thousands, $ in Thousands		Total		Cumulative Effect, Period of Adoption, Adjustment [Member]	Common Stock	Capital in Excess of Par Value	Retained Earnings	Retained Earnings Cumulative Effect, Period of Adoption, Adjustment [Member]	Treasury Stock	Accumulated Other Comprehensive Income (Loss)	Total  Synopsys Stockholders’ Equity	Non-controlling Interest
Balance (in shares) at Oct. 31, 2020					152,618
Beginning balance at Oct. 31, 2020		$ 4,912,367			$ 1,528	$ 1,653,166	$ 3,795,397		$ (488,613)	$ (54,074)	$ 4,907,404	$ 4,963
Beginning balance (Retained earnings adjustment due to adoption of ASC 326) at Oct. 31, 2020	[1]			$ (3,200)				$ (3,200)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		162,028					162,345				162,345	(317)
Other comprehensive income (loss), net of tax effects		$ 19,299								19,299	19,299
Purchases of treasury stock (in shares)		(837)	[2]		(837)
Purchases of treasury stock		$ (202,871)	[2]		$ (8)	8			(202,871)		(202,871)
Equity forward contract, net		$ (50,000)				(50,000)					(50,000)
Common stock issued, net of shares withheld for employee taxes (in shares)		583	[2]		583
Common stock issued, net of shares withheld for employee taxes		$ (34,507)			$ 6	(97,781)			63,268		(34,507)
Stock-based compensation		83,782				83,782					83,782
Balance (in shares) at Jan. 31, 2021					152,364
Ending balance at Jan. 31, 2021		4,886,898			$ 1,526	1,589,175	3,954,542		(628,216)	(34,775)	4,882,252	4,646
Balance (in shares) at Oct. 31, 2021					153,062
Beginning balance at Oct. 31, 2021		5,298,943			$ 1,531	1,576,363	4,549,713		(782,866)	(49,604)	5,295,137	3,806
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		313,341					313,687				313,687	(346)
Other comprehensive income (loss), net of tax effects		$ (1,853)								(1,853)	(1,853)
Purchases of treasury stock (in shares)		(701)	[3],[4]		(701)
Purchases of treasury stock		$ (245,000)	[3],[4]		$ (7)	7			(245,000)		(245,000)
Equity forward contract, net		$ (5,000)				(5,000)					(5,000)
Common stock issued, net of shares withheld for employee taxes (in shares)		895	[3],[4]		895
Common stock issued, net of shares withheld for employee taxes		$ (65,969)			$ 9	(236,915)			170,937		(65,969)
Stock-based compensation		95,771				95,771					95,771
Balance (in shares) at Jan. 31, 2022					153,256
Ending balance at Jan. 31, 2022		$ 5,390,233			$ 1,533	$ 1,430,226	$ 4,863,400		$ (856,929)	$ (51,457)	$ 5,386,773	$ 3,460

[1] In June 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standards Codification (ASC) 326, Measurement of Credit Losses on Financial Instruments, which replaces the incurred loss methodology with an expected loss methodology. We adopted the new standard at the beginning of fiscal 2021.

[2] Excluded the 166,726 shares and $50.0 million equity forward contract from the December 2020 ASR settled in March 2021.

[3] Excluded the 161,215 shares and $40.0 million equity forward contract from the December 2021 ASR settled in February 2022.

[4] Included 107,701 shares and $35.0 million equity forward contract from the August 2021 ASR settled in November 2021.