Consolidated Statements Of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total		Cumulative effect, period of adoption, adjustment	Common Stock	Capital in Excess of Par Value	Retained Earnings	Retained Earnings Cumulative effect, period of adoption, adjustment	Treasury Stock	Accumulated Other Comprehensive Income (Loss)	Total  Synopsys Stockholders’ Equity	Total  Synopsys Stockholders’ Equity Cumulative effect, period of adoption, adjustment	Non-controlling Interest
Balance (in shares) at Oct. 31, 2018				149,265
Beginning balance at Oct. 31, 2018	$ 3,485,015			$ 1,493	$ 1,644,830	$ 2,543,688		$ (597,682)	$ (113,177)	$ 3,479,152		$ 5,863
Beginning balance (Adjustment due to adoption of accounting standards related to revenue) at Oct. 31, 2018			$ 257,594				$ 257,594				$ 257,594
Beginning balance (Adjustment due to adoption of an accounting standard related to income taxes) at Oct. 31, 2018			(130,544)				(130,544)				$ (130,544)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	532,367					532,367				532,367
Other comprehensive income (loss), net of tax effects	$ 20,730								20,730	20,730
Purchases of treasury stock (in shares)	(2,732)			(2,732)
Purchases of treasury stock	$ (329,185)			$ (27)	27			(329,185)		(329,185)
Common stock issued, net of shares withheld for employee taxes (in shares)	3,798			3,798
Common stock issued, net of shares withheld for employee taxes	$ 99,103			$ 37	(163,198)	(38,961)		301,225		99,103
Stock-based compensation	153,796				153,796					153,796
Balance (in shares) at Oct. 31, 2019				150,331
Ending balance at Oct. 31, 2019	4,088,876			$ 1,503	1,635,455	3,164,144		(625,642)	(92,447)	4,083,013		5,863
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	663,447					664,347				664,347		(900)
Other comprehensive income (loss), net of tax effects	$ 38,373								38,373	38,373
Purchases of treasury stock (in shares)	(1,585)			(1,585)
Purchases of treasury stock	$ (242,078)			$ (14)	14			(242,078)		(242,078)
Common stock issued, net of shares withheld for employee taxes (in shares)	3,872			3,872
Common stock issued, net of shares withheld for employee taxes	$ 115,165			$ 39	(230,887)	(33,094)		379,107		115,165
Stock-based compensation	248,584				248,584					248,584
Balance (in shares) at Oct. 31, 2020				152,618
Ending 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
Ending balance (Adjustment related to reclassification of certain tax effects from accumulated other comprehensive income (loss)) at Oct. 31, 2020			$ (3,200)				$ (3,200)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	756,359					757,516				757,516		(1,157)
Other comprehensive income (loss), net of tax effects	$ 4,470								4,470	4,470
Purchases of treasury stock (in shares)	(2,780)	[1]		(2,780)
Purchases of treasury stock	$ (753,081)	[1]		$ (28)	28			(753,081)		(753,081)
Equity forward contract	$ (35,000)				(35,000)					(35,000)
Common stock issued, net of shares withheld for employee taxes (in shares)	3,224			3,224
Common stock issued, net of shares withheld for employee taxes	$ 71,756			$ 31	(387,103)			458,828		71,756
Stock-based compensation	345,272				345,272					345,272
Balance (in shares) at Oct. 31, 2021				153,062
Ending 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

[1] Excludes 107,701 shares and $35.0 million equity forward contract that was settled in November 2021.