Derivative Financial Instruments - Fair Value and Related Number of Derivative Contracts Categorized by Type of Derivative Contract (Details) $ in Thousands	Nov. 30, 2019 USD ($) Contract	Nov. 30, 2018 USD ($) Contract
Derivatives, Fair Value [Line Items]
Net amounts per Consolidated Statements of Financial Condition, Assets	$ 397,551	$ 130,610
Net amounts per Consolidated Statements of Financial Condition, Liabilities	527,205	1,127,651
Exchange-traded
Derivatives, Fair Value [Line Items]
Fair Value, Assets	718,685	1,204,106
Fair Value, Liabilities	962,638	2,061,922
Amounts offset in the Consolidated Statements of Financial Condition, Assets	(688,871)	(1,190,951)
Amounts offset in the Consolidated Statements of Financial Condition, Liabilities	(688,871)	(1,190,951)
Cleared OTC
Derivatives, Fair Value [Line Items]
Fair Value, Assets	244,401	433,874
Fair Value, Liabilities	290,201	443,072
Amounts offset in the Consolidated Statements of Financial Condition, Assets	(222,869)	(407,351)
Amounts offset in the Consolidated Statements of Financial Condition, Liabilities	(266,900)	(418,779)
Bilateral OTC
Derivatives, Fair Value [Line Items]
Fair Value, Assets	867,271	905,116
Fair Value, Liabilities	906,153	1,134,262
Amounts offset in the Consolidated Statements of Financial Condition, Assets	(521,066)	(814,184)
Amounts offset in the Consolidated Statements of Financial Condition, Liabilities	(676,016)	(901,875)
Derivatives designated as accounting hedges:
Derivatives, Fair Value [Line Items]
Fair Value, Assets	28,663	0
Fair Value, Liabilities	0	29,647
Derivatives designated as accounting hedges: \| Interest rate contracts: \| Cleared OTC
Derivatives, Fair Value [Line Items]
Fair Value, Assets	$ 28,663	$ 0
Number of Contracts, Assets \| Contract	1	0
Fair Value, Liabilities	$ 0	$ 29,647
Number of Contracts, Liabilities \| Contract		1
Derivatives not designated as accounting hedges:
Derivatives, Fair Value [Line Items]
Fair Value, Assets	$ 1,801,694	$ 2,543,096
Fair Value, Liabilities	2,158,992	3,609,609
Derivatives not designated as accounting hedges: \| Interest rate contracts: \| Exchange-traded
Derivatives, Fair Value [Line Items]
Fair Value, Assets	$ 1,191	$ 924
Number of Contracts, Assets \| Contract	65,226	32,159
Fair Value, Liabilities	$ 103	$ 513
Number of Contracts, Liabilities \| Contract	38,464	66,095
Derivatives not designated as accounting hedges: \| Interest rate contracts: \| Cleared OTC
Derivatives, Fair Value [Line Items]
Fair Value, Assets	$ 213,224	$ 422,670
Number of Contracts, Assets \| Contract	3,329	2,095
Fair Value, Liabilities	$ 284,433	$ 411,833
Number of Contracts, Liabilities \| Contract	3,443	2,394
Derivatives not designated as accounting hedges: \| Interest rate contracts: \| Bilateral OTC
Derivatives, Fair Value [Line Items]
Fair Value, Assets	$ 421,700	$ 372,899
Number of Contracts, Assets \| Contract	1,325	1,398
Fair Value, Liabilities	$ 258,857	$ 491,697
Number of Contracts, Liabilities \| Contract	738	816
Derivatives not designated as accounting hedges: \| Foreign exchange contracts: \| Exchange-traded
Derivatives, Fair Value [Line Items]
Fair Value, Assets	$ 0	$ 42
Number of Contracts, Assets \| Contract	256	538
Fair Value, Liabilities	$ 0	$ 2
Number of Contracts, Liabilities \| Contract	199	690
Derivatives not designated as accounting hedges: \| Foreign exchange contracts: \| Cleared OTC
Derivatives, Fair Value [Line Items]
Fair Value, Assets		$ 0
Number of Contracts, Assets \| Contract		0
Fair Value, Liabilities		$ 36
Number of Contracts, Liabilities \| Contract		3
Derivatives not designated as accounting hedges: \| Foreign exchange contracts: \| Bilateral OTC
Derivatives, Fair Value [Line Items]
Fair Value, Assets	$ 190,570	$ 311,228
Number of Contracts, Assets \| Contract	9,255	9,548
Fair Value, Liabilities	$ 187,836	$ 314,951
Number of Contracts, Liabilities \| Contract	9,187	9,909
Derivatives not designated as accounting hedges: \| Equity contracts: \| Exchange-traded
Derivatives, Fair Value [Line Items]
Fair Value, Assets	$ 717,494	$ 1,202,927
Number of Contracts, Assets \| Contract	1,714,538	2,104,684
Fair Value, Liabilities	$ 962,535	$ 2,061,137
Number of Contracts, Liabilities \| Contract	1,481,388	1,779,836
Derivatives not designated as accounting hedges: \| Equity contracts: \| Bilateral OTC
Derivatives, Fair Value [Line Items]
Fair Value, Assets	$ 248,720	$ 207,221
Number of Contracts, Assets \| Contract	4,731	5,126
Fair Value, Liabilities	$ 445,241	$ 315,996
Number of Contracts, Liabilities \| Contract	4,271	2,764
Derivatives not designated as accounting hedges: \| Commodity contracts: \| Exchange-traded
Derivatives, Fair Value [Line Items]
Fair Value, Assets	$ 0	$ 213
Number of Contracts, Assets \| Contract	5,524	3,927
Fair Value, Liabilities	$ 0	$ 270
Number of Contracts, Liabilities \| Contract	4,646	4,012
Derivatives not designated as accounting hedges: \| Credit contracts: \| Cleared OTC
Derivatives, Fair Value [Line Items]
Fair Value, Assets	$ 2,514	$ 11,204
Number of Contracts, Assets \| Contract	13	7
Fair Value, Liabilities	$ 5,768	$ 1,556
Number of Contracts, Liabilities \| Contract	12	14
Derivatives not designated as accounting hedges: \| Credit contracts: \| Bilateral OTC
Derivatives, Fair Value [Line Items]
Fair Value, Assets	$ 6,281	$ 13,768
Number of Contracts, Assets \| Contract	25	123
Fair Value, Liabilities	$ 14,219	$ 11,618
Number of Contracts, Liabilities \| Contract	28	79

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