Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2018
Cash flow from operating activities:
Net income attributed to Synopsys	$ 664,347	$ 532,367	$ 432,518
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization and depreciation	209,986	201,676	209,207
Reduction of operating lease right-of-use assets	82,895	0	0
Amortization of capitalized costs to obtain revenue contracts	61,185	62,750	0
Stock-based compensation	248,584	155,001	140,032
Allowance for doubtful accounts	20,875	11,669	3,368
(Gain) loss on sale of property and investments	(1,994)	(4,052)	(93)
Deferred income taxes	(111,526)	(82,620)	(210,310)
Other non-cash	5,419	(993)	(851)
Net changes in operating assets and liabilities, net of acquired assets and liabilities:
Accounts receivable	(236,806)	(8,575)	(95,785)
Inventories	(55,024)	(17,396)	(65,751)
Prepaid and other current assets	(11,298)	(49,779)	(12,652)
Other long-term assets	(83,367)	(125,749)	(25,815)
Accounts payable and accrued liabilities	113,773	(19,280)	49,043
Operating lease liabilities	(78,578)	0	0
Income taxes	14,120	19,777	(103,841)
Deferred revenue	148,722	125,717	105,329
Net cash provided by operating activities	991,313	800,513	424,399
Cash flows from investing activities:
Proceeds from sales and maturities of short-term investments	0	0	12,449
Proceeds from sales of long-term investments	2,151	6,361	494
Purchases of long-term investments	(2,762)	(3,245)	(3,561)
Proceeds from sale of property and equipment	0	0	1,662
Purchases of property and equipment	(154,717)	(198,129)	(98,976)
Cash paid for acquisitions and intangible assets, net of cash acquired	(201,045)	(36,605)	(652,643)
Capitalization of software development costs	(4,045)	(4,259)	(2,950)
Net cash used in investing activities	(360,418)	(235,877)	(743,525)
Cash flows from financing activities:
Proceeds from credit facilities	276,489	192,897	620,635
Repayment of debt	(288,879)	(524,063)	(295,313)
Issuances of common stock	197,403	156,364	123,829
Payments for taxes related to net share settlement of equity awards	(82,225)	(57,143)	(45,772)
Purchases of treasury stock	(242,078)	(329,185)	(400,000)
Other	(1,316)	(762)	1,759
Net cash (used in) provided by financing activities	(140,606)	(561,892)	5,138
Effect of exchange rate changes on cash, cash equivalents and restricted cash	17,154	2,782	(11,086)
Net change in cash, cash equivalents and restricted cash	507,443	5,526	(325,074)
Cash, cash equivalents and restricted cash, beginning of year	730,527	725,001	1,050,075
Cash, cash equivalents and restricted cash, end of year	1,237,970	730,527	725,001
Supplemental disclosure of cash flow information:
Cash paid for income taxes during the year:	70,711	75,744	252,522
Interest payments during the year:	$ 5,136	$ 12,363	$ 15,307