Revenue - Schedule of Disaggregation of Revenue (Details)	3 Months Ended		6 Months Ended
	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2020	Apr. 30, 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	60.00%	58.00%	60.00%	59.00%
IP & System Integration
Disaggregation of Revenue [Line Items]
Revenue percentage by product group	30.00%	31.00%	30.00%	30.00%
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%	1.00%	0.00%	1.00%