Revenue - Schedule of Disaggregation of Revenue (Details)	3 Months Ended		9 Months Ended
	Jul. 31, 2020	Jul. 31, 2019	Jul. 31, 2020	Jul. 31, 2019
Disaggregation of Revenue [Line Items]
Revenue percentage by product group	100.00%	100.00%	100.00%	100.00%
EDA
Disaggregation of Revenue [Line Items]
Revenue percentage by product group	55.00%	57.00%	58.00%	59.00%
IP & System Integration
Disaggregation of Revenue [Line Items]
Revenue percentage by product group	35.00%	33.00%	32.00%	31.00%
Software Integrity Products & Services
Disaggregation of Revenue [Line Items]
Revenue percentage by product group	10.00%	10.00%	10.00%	10.00%
Other
Disaggregation of Revenue [Line Items]
Revenue percentage by product group	0.00%	0.00%	0.00%	0.00%