Financial Assets and Liabilities - Short-term investments (Details) - Cash equivalents - USD ($) $ in Thousands |
Jul. 31, 2019 |
Oct. 31, 2018 |
---|---|---|
Debt Securities, Available-for-sale [Line Items] | ||
Available-for-sale securities, cost | $ 130,437 | $ 165,296 |
Gross unrealized gains | 0 | 0 |
Gross unrealized losses less than 12 months | 0 | 0 |
Gross unrealized losses 12 months or longer | 0 | 0 |
Estimated fair value | 130,437 | 165,296 |
Money market funds | ||
Debt Securities, Available-for-sale [Line Items] | ||
Available-for-sale securities, cost | 130,437 | 165,296 |
Gross unrealized gains | 0 | 0 |
Gross unrealized losses less than 12 months | 0 | 0 |
Gross unrealized losses 12 months or longer | 0 | 0 |
Estimated fair value | $ 130,437 | $ 165,296 |