Derivative Financial Instruments - Fair Value and Related Number of Derivative Contracts Categorized by Type of Derivative Contract (Detail) (USD $) In Thousands, unless otherwise specified	Feb. 28, 2014	Nov. 30, 2013
Derivatives, Fair Value [Line Items]
Net amounts per Consolidated Statements of Financial Condition, Assets	$ 223,699	$ 261,093
Net amounts per Consolidated Statements of Financial Condition, Liabilities	188,505	180,079
Exchange-traded [Member]
Derivatives, Fair Value [Line Items]
Fair Value, Assets	454,221	530,983
Number of Contracts, Assets
Fair Value, Liabilities	456,816	502,657
Number of Contracts, Liabilities
Amounts offset in the Consolidated Statements of Financial Condition, Assets	(448,484)	(489,375)
Amounts offset in the Consolidated Statements of Financial Condition, Liabilities	(448,484)	(489,375)
Cleared OTC [Member]
Derivatives, Fair Value [Line Items]
Fair Value, Assets	533,659	482,198
Number of Contracts, Assets
Fair Value, Liabilities	539,077	448,054
Number of Contracts, Liabilities
Amounts offset in the Consolidated Statements of Financial Condition, Assets	(522,286)	(446,520)
Amounts offset in the Consolidated Statements of Financial Condition, Liabilities	(514,335)	(445,106)
Bilateral OTC [Member]
Derivatives, Fair Value [Line Items]
Fair Value, Assets	1,408,336	1,501,501
Number of Contracts, Assets
Fair Value, Liabilities	1,414,178	1,582,979
Number of Contracts, Liabilities
Amounts offset in the Consolidated Statements of Financial Condition, Assets	(1,201,747)	(1,317,694)
Amounts offset in the Consolidated Statements of Financial Condition, Liabilities	(1,258,747)	(1,418,130)
Interest rate contracts [Member] \| Exchange-traded [Member]
Derivatives, Fair Value [Line Items]
Fair Value, Assets	4,265	8,696
Number of Contracts, Assets	40,007	57,344
Fair Value, Liabilities	7,670	3,846
Number of Contracts, Liabilities	47,510	68,268
Interest rate contracts [Member] \| Cleared OTC [Member]
Derivatives, Fair Value [Line Items]
Fair Value, Assets	519,964	432,667
Number of Contracts, Assets	2,222	5,402
Fair Value, Liabilities	523,532	396,422
Number of Contracts, Liabilities	1,964	7,730
Interest rate contracts [Member] \| Bilateral OTC [Member]
Derivatives, Fair Value [Line Items]
Fair Value, Assets	711,837	724,613
Number of Contracts, Assets	1,190	1,221
Fair Value, Liabilities	677,525	730,897
Number of Contracts, Liabilities	612	1,340
Foreign exchange contracts [Member] \| Exchange-traded [Member]
Derivatives, Fair Value [Line Items]
Fair Value, Assets	29	33
Number of Contracts, Assets	56,669	111,229
Fair Value, Liabilities	68	40
Number of Contracts, Liabilities	66,613	104,205
Foreign exchange contracts [Member] \| Bilateral OTC [Member]
Derivatives, Fair Value [Line Items]
Fair Value, Assets	582,894	653,739
Number of Contracts, Assets	9,665	7,478
Fair Value, Liabilities	622,707	693,618
Number of Contracts, Liabilities	11,809	8,212
Equity contracts [Member] \| Exchange-traded [Member]
Derivatives, Fair Value [Line Items]
Fair Value, Assets	423,076	495,069
Number of Contracts, Assets	1,441,414	1,742,195
Fair Value, Liabilities	421,531	465,110
Number of Contracts, Liabilities	1,446,583	1,800,467
Equity contracts [Member] \| Bilateral OTC [Member]
Derivatives, Fair Value [Line Items]
Fair Value, Assets	3,640	6,715
Number of Contracts, Assets	96	148
Fair Value, Liabilities	13,418	9,875
Number of Contracts, Liabilities	104	136
Commodity contracts [Member] \| Exchange-traded [Member]
Derivatives, Fair Value [Line Items]
Fair Value, Assets	26,851	27,185
Number of Contracts, Assets	678,154	785,718
Fair Value, Liabilities	27,547	33,661
Number of Contracts, Liabilities	698,329	780,358
Commodity contracts [Member] \| Bilateral OTC [Member]
Derivatives, Fair Value [Line Items]
Fair Value, Assets	106,004	114,095
Number of Contracts, Assets	4,062	11,811
Fair Value, Liabilities	88,289	139,458
Number of Contracts, Liabilities	3,173	8,359
Credit contracts [Member] \| Cleared OTC [Member]
Derivatives, Fair Value [Line Items]
Fair Value, Assets	13,695	49,531
Number of Contracts, Assets	17	49
Fair Value, Liabilities	15,545	51,632
Number of Contracts, Liabilities	14	46
Credit contracts [Member] \| Bilateral OTC [Member]
Derivatives, Fair Value [Line Items]
Fair Value, Assets	3,961	2,339
Number of Contracts, Assets	19	16
Fair Value, Liabilities	$ 12,239	$ 8,131
Number of Contracts, Liabilities	26	19

The number of derivative instruments of a particular derivative asset or group of derivative assets held by the entity.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

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- Definition

Fair value of derivative asset, presented on a gross basis even when the derivative instrument is subject to master netting arrangements and qualifies for net presentation in the statement of financial position.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 205G

-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 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

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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 3: http://www.xbrl.org/2003/role/presentationRef

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-Name Accounting Standards Codification

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The amount as of the balance sheet date of the fair value of derivative assets that in accordance with the entity's accounting policy was offset against an obligation to return cash collateral under a master netting arrangement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 8

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-Name FASB Staff Position (FSP)

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- Definition

Fair value of derivative liability, presented on a gross basis even when the derivative instrument is subject to master netting arrangements and qualifies for net presentation in the statement of financial position.

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The amount as of the balance sheet date of the fair value of derivative liabilities that in accordance with the entity's accounting policy were offset against the right to reclaim cash collateral under a master netting arrangement.

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- Definition

The number of derivative instruments of a particular derivative liability or group of derivative liabilities held by the entity.

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The fair value as of the balance sheet date of firm holdings in all assets resulting from contracts that meet the criteria of being accounted for as derivative instruments. Their value is derived from the values of one or more underlying assets, reference rates, or indices of asset values. Includes both pledged (to counterparties as collateral for financing transactions) and unpledged holdings.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 4

-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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- Definition

Fair value of obligations arising from derivatives and other contracts sold short.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 940

-SubTopic 320

-Section 35

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6475908&loc=d3e42429-110968

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