Unaudited Condensed Consolidated Statements of Stockholders' Equity Statement - USD ($) shares in Thousands, $ in Thousands		Total	Common Stock	Capital in Excess of Par Value	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Income (Loss)	Total Synopsys Stockholders’ Equity	Non-controlling Interest
Balance (in shares) at Oct. 31, 2017			150,445
Beginning balance at Oct. 31, 2017		$ 3,279,724	$ 1,505	$ 1,622,429	$ 2,143,873	$ (426,208)	$ (65,979)	$ 3,275,620	$ 4,104
Net income		(3,691)			(3,691)			(3,691)
Other comprehensive income (loss), net of tax effects		28,787					28,787	28,787
Purchases of treasury stock (in shares)			(1,987)
Purchases of treasury stock, value		(180,000)	$ (20)	20		(180,000)		(180,000)
Equity forward contract		(20,000)		(20,000)				(20,000)
Common stock Issued, net of shares withheld for employee taxes (in shares)			495
Common stock issued, net of shares withheld for employee taxes		3,700	$ 5	(22,103)	(6,328)	32,126		3,700
Stock-based compensation		32,113		32,113				32,113
Balance (in shares) at Jan. 31, 2018			148,953
Ending balance at Jan. 31, 2018		3,140,633	$ 1,490	1,612,459	2,133,854	(574,082)	(37,192)	3,136,529	4,104
Balance (in shares) at Oct. 31, 2017			150,445
Beginning balance at Oct. 31, 2017		3,279,724	$ 1,505	1,622,429	2,143,873	(426,208)	(65,979)	3,275,620	4,104
Net income		98,781
Other comprehensive income (loss), net of tax effects		$ 3,590
Purchases of treasury stock (in shares)		(2,902)
Purchases of treasury stock, value		$ (255,000)
Common stock Issued, net of shares withheld for employee taxes (in shares)		1,419
Balance (in shares) at Apr. 30, 2018			148,961
Ending balance at Apr. 30, 2018		$ 3,260,397	$ 1,490	1,678,921	2,223,287	(585,016)	(62,389)	3,256,293	4,104
Balance (in shares) at Jan. 31, 2018			148,953
Beginning balance at Jan. 31, 2018		3,140,633	$ 1,490	1,612,459	2,133,854	(574,082)	(37,192)	3,136,529	4,104
Net income		102,472						102,472
Other comprehensive income (loss), net of tax effects		$ (25,197)					(25,197)	(25,197)
Purchases of treasury stock (in shares)		(916)	(916)
Purchases of treasury stock, value		$ (75,000)	$ (9)	9		(75,000)		(75,000)
Equity forward contract		$ 40,000		40,000				40,000
Common stock Issued, net of shares withheld for employee taxes (in shares)		924	924
Common stock issued, net of shares withheld for employee taxes		$ 45,133	$ 9	(6,196)	(12,746)	64,066		45,133
Stock-based compensation		32,649		32,649				32,649
Balance (in shares) at Apr. 30, 2018			148,961
Ending balance at Apr. 30, 2018		3,260,397	$ 1,490	1,678,921	2,223,287	(585,016)	(62,389)	3,256,293	4,104
Cumulative Effect of New Accounting Principle in Period of Adoption | AccountingStandardsUpdate201802	[1]	(293)			(293)			(293)
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
Net income		153,514			153,514			153,514
Other comprehensive income (loss), net of tax effects		15,325					15,325	15,325
Purchases of treasury stock (in shares)			(346)
Purchases of treasury stock, value		(29,185)	$ (3)	3		(29,185)		(29,185)
Common stock Issued, net of shares withheld for employee taxes (in shares)			357
Common stock issued, net of shares withheld for employee taxes		(4,320)	$ 3	(27,736)	(3,342)	26,755		(4,320)
Stock-based compensation		37,266		37,266				37,266
Balance (in shares) at Jan. 31, 2019			149,276
Ending balance at Jan. 31, 2019		3,784,665	$ 1,493	1,654,363	2,820,910	(600,112)	(97,852)	3,778,802	5,863
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
Net income		271,724
Other comprehensive income (loss), net of tax effects		$ 16,457
Purchases of treasury stock (in shares)		(1,126)
Purchases of treasury stock, value		$ (109,185)
Common stock Issued, net of shares withheld for employee taxes (in shares)		1,843
Balance (in shares) at Apr. 30, 2019			149,982
Ending balance at Apr. 30, 2019		$ 3,915,435	$ 1,500	1,659,484	2,912,811	(567,503)	(96,720)	3,909,572	5,863
Cumulative Effect of New Accounting Principle in Period of Adoption | Accounting Standards Update 2014-09	[1]	257,594			257,594			257,594
Cumulative Effect of New Accounting Principle in Period of Adoption | Accounting Standards Update 2016-16	[2]	(130,544)			(130,544)			(130,544)
Balance (in shares) at Jan. 31, 2019			149,276
Beginning balance at Jan. 31, 2019		3,784,665	$ 1,493	1,654,363	2,820,910	(600,112)	(97,852)	3,778,802	5,863
Net income		118,210			118,210			118,210
Other comprehensive income (loss), net of tax effects		$ 1,132					1,132	1,132
Purchases of treasury stock (in shares)		(780)	(780)
Purchases of treasury stock, value		$ (80,000)	$ (8)	8		(80,000)		(80,000)
Equity forward contract		$ (20,000)		(20,000)				(20,000)
Common stock Issued, net of shares withheld for employee taxes (in shares)		1,486	1,486
Common stock issued, net of shares withheld for employee taxes		$ 74,520	$ 15	(11,795)	(26,309)	112,609		74,520
Stock-based compensation		36,908		36,908				36,908
Balance (in shares) at Apr. 30, 2019			149,982
Ending balance at Apr. 30, 2019		$ 3,915,435	$ 1,500	$ 1,659,484	$ 2,912,811	$ (567,503)	$ (96,720)	$ 3,909,572	$ 5,863

[1] See Note 2. Summary of Significant Accounting Policies for additional information on the retained earnings adjustment due to adoption of Accounting Standards Codification (ASC) 606 and ASC 340.

[2] See Note 14. Taxes for additional information on the retained earnings adjustment due to adoption of Accounting Standard Update (ASU) 2016-16.