Financial Assets and Liabilities - Short-term investments (Details) - USD ($) $ in Thousands		Jul. 31, 2021		Oct. 31, 2020
Cash Equivalents [Line Items]
Cost		$ 144,758
Gross unrealized gains		51
Gross unrealized losses less than 12 months		(36)
Gross unrealized losses 12 months or longer		0
Estimated fair value	[1]	144,773
Cash equivalents
Cash Equivalents [Line Items]
Cost		252,894		$ 304,127
Gross unrealized gains		0		0
Gross unrealized losses less than 12 months		(1)		0
Gross unrealized losses 12 months or longer		0		0
Estimated fair value		252,893	[1]	304,127	[2]
Cash equivalents | Money market funds
Cash Equivalents [Line Items]
Cost		249,814		304,127
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		249,814	[1]	$ 304,127	[2]
Cash equivalents | Corporate debt securities
Cash Equivalents [Line Items]
Cost		3,080
Gross unrealized gains		0
Gross unrealized losses less than 12 months		(1)
Gross unrealized losses 12 months or longer		0
Estimated fair value	[1]	3,079
Short-term investments | Corporate debt securities
Cash Equivalents [Line Items]
Cost		100,308
Gross unrealized gains		38
Gross unrealized losses less than 12 months		(28)
Gross unrealized losses 12 months or longer		0
Estimated fair value	[1]	100,318
Short-term investments | U.S. government agency & T-bills
Cash Equivalents [Line Items]
Cost		7,745
Gross unrealized gains		2
Gross unrealized losses less than 12 months		0
Gross unrealized losses 12 months or longer		0
Estimated fair value	[1]	7,747
Short-term investments | Municipal bonds
Cash Equivalents [Line Items]
Cost		2,465
Gross unrealized gains		1
Gross unrealized losses less than 12 months		0
Gross unrealized losses 12 months or longer		0
Estimated fair value	[1]	2,466
Short-term investments | Asset-backed securities
Cash Equivalents [Line Items]
Cost		33,502
Gross unrealized gains		10
Gross unrealized losses less than 12 months		(7)
Gross unrealized losses 12 months or longer		0
Estimated fair value	[1]	33,505
Short-term investments | Others
Cash Equivalents [Line Items]
Cost		738
Gross unrealized gains		0
Gross unrealized losses less than 12 months		(1)
Gross unrealized losses 12 months or longer		0
Estimated fair value	[1]	$ 737

[1] See Note 7. Fair Value Measures for further discussion on fair values of cash equivalents and short-term investments.

[2] See Note 7. Fair Value Measures for further discussion on fair values of cash equivalents.