Financial Assets And Liabilities (Summary Of Cash, Cash Equivalents And Investments) (Details) (USD $) In Thousands, unless otherwise specified	Apr. 30, 2012		Oct. 31, 2011
Financial Assets And Liabilities [Line Items]
Cost	$ 801,007		$ 1,007,909
Gross Unrealized Gains			296
Gross Unrealized Losses Less Than 12 Months			(149)
Estimated Fair Value	801,007	[1]	1,008,056	[1]
Classified As Current Assets, Total [Member]
Financial Assets And Liabilities [Line Items]
Cost	796,594		1,003,927
Gross Unrealized Gains			296
Gross Unrealized Losses Less Than 12 Months			(149)
Estimated Fair Value	796,594	[1]	1,004,074	[1]
Non-Interest Bearing Cash (U.S. And International) [Member]
Financial Assets And Liabilities [Line Items]
Cost	194,432		149,998
Estimated Fair Value	194,432	[1]	149,998	[1]
Money Market Funds (U.S.) [Member]
Financial Assets And Liabilities [Line Items]
Cost	90,000		55,267
Estimated Fair Value	90,000	[1]	55,267	[1]
Cash Deposits And Money Market Funds (International) [Member]
Financial Assets And Liabilities [Line Items]
Cost	512,162		649,812
Estimated Fair Value	512,162	[1]	649,812	[1]
Strategic Investments [Member]
Financial Assets And Liabilities [Line Items]
Cost	4,413		3,982
Estimated Fair Value	4,413	[1]	3,982	[1]
Municipal Securities [Member]
Financial Assets And Liabilities [Line Items]
Cost			148,850
Gross Unrealized Gains			296
Gross Unrealized Losses Less Than 12 Months			(149)
Estimated Fair Value			$ 148,997	[1]

[1] See Note 5 for further discussion of fair values.