Financial Assets and Liabilities - Summary of Cash Cash Equivalents and Investments (Detail) - USD ($) $ in Thousands	Oct. 31, 2018	Oct. 31, 2017
Cash equivalents:
Cash, Cash Equivalents and Investments [Line Items]
Available-for-sale Securities, Cost	$ 165,296	$ 560,594
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	165,296	560,594
Other long-term assets:
Cash, Cash Equivalents and Investments [Line Items]
Non-marketable equity securities, Cost	10,892	7,826
Gross Unrealized Gains	0	0
Gross Unrealized Losses Less Than 12Months	0	0
Gross Unrealized Loss Position 12Months Or Longer	0	0
Non-marketable equity securities	10,892	7,826
Money market funds | Cash equivalents:
Cash, Cash Equivalents and Investments [Line Items]
Available-for-sale Securities, Cost	165,296	560,594
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	165,296	560,594
Non-marketable equity securities | Other long-term assets:
Cash, Cash Equivalents and Investments [Line Items]
Non-marketable equity securities, Cost	10,892	7,826
Gross Unrealized Gains	0	0
Gross Unrealized Losses Less Than 12Months	0	0
Gross Unrealized Loss Position 12Months Or Longer	0	0
Non-marketable equity securities	$ 10,892	$ 7,826