Investments (Summary Of Marketable Securities Classified As Available-For-Sale) (Details) (USD $) In Thousands, unless otherwise specified	Nov. 30, 2013	Nov. 30, 2012
Investments [Line Items]
Purchased/Amortized Cost	$ 330,143	$ 411,461
Gross Unrealized Gains	188	87
Gross Unrealized Losses	0	(62)
Aggregate Fair Value	330,331	411,486
Money market funds
Investments [Line Items]
Purchased/Amortized Cost	245,953	376,480
Aggregate Fair Value	245,953	376,480
Corporate bonds and commercial paper
Investments [Line Items]
Purchased/Amortized Cost	77,442	24,558
Gross Unrealized Gains	66	9
Gross Unrealized Losses	0	(9)
Aggregate Fair Value	77,508	24,558
U.S Government debt and agency securities
Investments [Line Items]
Purchased/Amortized Cost	6,012	9,646
Gross Unrealized Gains	1	0
Gross Unrealized Losses	0	(1)
Aggregate Fair Value	6,013	9,645
Term deposits
Investments [Line Items]
Purchased/Amortized Cost	536	595
Aggregate Fair Value	536	595
Mortgage-backed securities
Investments [Line Items]
Purchased/Amortized Cost	200	182
Gross Unrealized Gains	121	78
Gross Unrealized Losses	0	(52)
Aggregate Fair Value	$ 321	$ 208

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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Reference 5: http://www.xbrl.org/2003/role/presentationRef

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 6: http://www.xbrl.org/2003/role/presentationRef

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 7: http://www.xbrl.org/2003/role/presentationRef

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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+ Details

- Definition

This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

+ References+ Details

- Definition

This item represents the gross unrealized gains for securities, at a point in time, which are categorized neither as held-to-maturity nor trading securities.

+ References+ Details