Fair Value Disclosures - Financial Assets and Liabilities Accounted for at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	Aug. 31, 2016	Nov. 30, 2015
Financial instruments owned:
Corporate equity securities	$ 2,149,879	$ 2,027,989
Corporate debt securities	2,529,310	2,893,041
CDOs and CLOs	143,864	174,236
U.S. government and federal agency securities	3,143,852	2,645,651
Municipal securities	577,467	487,141
Sovereign obligations	2,035,035	2,659,441
Loans and other receivables	1,401,549	1,312,333
Derivatives	330,582	251,080
Investments at fair value	85,036	79,344
Total financial instruments owned, excluding Investments at fair value based on NAV	14,298,419	16,522,382
Counterparty and Cash Collateral Netting	(5,887,874)	(4,165,446)
Cash and cash equivalents	3,159,143	3,510,163
Cash and securities segregated and on deposit for regulatory purposes	1,026,865	751,084
Financial instruments sold, not yet purchased:
Corporate equity securities	1,741,068	1,418,933
Corporate debt securities	1,705,150	1,556,941
U.S. government and federal agency securities	1,213,672	1,488,121
Sovereign obligations	2,373,031	1,342,996
Loans	539,028	769,408
Derivatives	372,123	208,548
Total financial instruments sold, not yet purchased	7,944,072	6,785,064
Counterparty and Cash Collateral Netting	(5,970,029)	(4,257,998)
Other secured financings	53,586	68,345
Long-term debt	204,422	0
US Treasury Securities [Member]
Financial instruments owned:
Cash and securities segregated and on deposit for regulatory purposes	99,900
RMBS [Member]
Financial instruments owned:
Mortgage- and asset-backed securities, assets	1,378,840	2,801,333
Financial instruments sold, not yet purchased:
Residential mortgaged-backed securities		117
Commercial mortgage-backed securities [Member]
Financial instruments owned:
Mortgage- and asset-backed securities, assets	345,505	1,029,239
Other asset-backed securities [Member]
Financial instruments owned:
Mortgage- and asset-backed securities, assets	177,500	161,554
Level 1 [Member]
Financial instruments owned:
Corporate equity securities	2,019,490	1,853,351
Corporate debt securities	0	0
CDOs and CLOs	0	0
U.S. government and federal agency securities	3,029,251	2,555,018
Municipal securities	0	0
Sovereign obligations	904,592	1,251,366
Loans and other receivables	0	0
Derivatives	2,530	1,037
Investments at fair value	0	0
Total financial instruments owned, excluding Investments at fair value based on NAV	5,955,863	5,660,772
Cash and cash equivalents	3,159,143	3,510,163
Cash and securities segregated and on deposit for regulatory purposes	1,026,865	751,084
Financial instruments sold, not yet purchased:
Corporate equity securities	1,682,196	1,382,377
Corporate debt securities	0	0
U.S. government and federal agency securities	1,213,672	1,488,121
Sovereign obligations	940,451	837,614
Loans	0	0
Derivatives	373	364
Total financial instruments sold, not yet purchased	3,836,692	3,708,476
Other secured financings	0	0
Long-term debt	0
Level 1 [Member] \| RMBS [Member]
Financial instruments owned:
Mortgage- and asset-backed securities, assets	0	0
Financial instruments sold, not yet purchased:
Residential mortgaged-backed securities		0
Level 1 [Member] \| Commercial mortgage-backed securities [Member]
Financial instruments owned:
Mortgage- and asset-backed securities, assets	0	0
Level 1 [Member] \| Other asset-backed securities [Member]
Financial instruments owned:
Mortgage- and asset-backed securities, assets	0	0
Level 2 [Member]
Financial instruments owned:
Corporate equity securities	108,194	133,732
Corporate debt securities	2,494,303	2,867,165
CDOs and CLOs	99,794	89,144
U.S. government and federal agency securities	114,601	90,633
Municipal securities	550,210	487,141
Sovereign obligations	1,130,443	1,407,955
Loans and other receivables	1,323,092	1,123,044
Derivatives	6,206,366	4,395,704
Investments at fair value	0	26,224
Total financial instruments owned, excluding Investments at fair value based on NAV	13,796,262	14,485,354
Cash and cash equivalents	0	0
Cash and securities segregated and on deposit for regulatory purposes	0	0
Financial instruments sold, not yet purchased:
Corporate equity securities	58,834	36,518
Corporate debt securities	1,704,627	1,556,941
U.S. government and federal agency securities	0	0
Sovereign obligations	1,432,580	505,382
Loans	538,180	758,939
Derivatives	6,321,172	4,446,639
Total financial instruments sold, not yet purchased	10,055,393	7,304,536
Other secured financings	53,318	67,801
Long-term debt	204,422
Level 2 [Member] \| RMBS [Member]
Financial instruments owned:
Mortgage- and asset-backed securities, assets	1,331,959	2,731,070
Financial instruments sold, not yet purchased:
Residential mortgaged-backed securities		117
Level 2 [Member] \| Commercial mortgage-backed securities [Member]
Financial instruments owned:
Mortgage- and asset-backed securities, assets	320,912	1,014,913
Level 2 [Member] \| Other asset-backed securities [Member]
Financial instruments owned:
Mortgage- and asset-backed securities, assets	116,388	118,629
Level 3 [Member]
Financial instruments owned:
Corporate equity securities	22,195	40,906
Corporate debt securities	35,007	25,876
CDOs and CLOs	44,070	85,092
U.S. government and federal agency securities	0	0
Municipal securities	27,257	0
Sovereign obligations	0	120
Loans and other receivables	78,457	189,289
Derivatives	9,560	19,785
Investments at fair value	85,036	53,120
Total financial instruments owned, excluding Investments at fair value based on NAV	434,168	541,702
Cash and cash equivalents	0	0
Cash and securities segregated and on deposit for regulatory purposes	0	0
Financial instruments sold, not yet purchased:
Corporate equity securities	38	38
Corporate debt securities	523	0
U.S. government and federal agency securities	0	0
Sovereign obligations	0	0
Loans	848	10,469
Derivatives	20,607	19,543
Total financial instruments sold, not yet purchased	22,016	30,050
Other secured financings	268	544
Long-term debt	0
Level 3 [Member] \| RMBS [Member]
Financial instruments owned:
Mortgage- and asset-backed securities, assets	46,881	70,263
Financial instruments sold, not yet purchased:
Residential mortgaged-backed securities		0
Level 3 [Member] \| Commercial mortgage-backed securities [Member]
Financial instruments owned:
Mortgage- and asset-backed securities, assets	24,593	14,326
Level 3 [Member] \| Other asset-backed securities [Member]
Financial instruments owned:
Mortgage- and asset-backed securities, assets	$ 61,112	$ 42,925

Fair value of loan obligations.

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The fair value as of the balance sheet date of firm holdings in structured asset - backed securities whose value and payments are derived from portfolio of fixed income underlying assets.

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The fair value as of the balance sheet date of firm holdings in corporate loans, participation certificates in GNMA project and construction loans, and escrow and trade claim receivables.

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Financial Instruments, Owned, at Fair Value Excluding Investments at Net Asset Value

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Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Amount of cash subject to withdrawal restrictions, restricted deposits held as compensating balances, and cash and securities segregated in compliance with regulations (such as cash deposited in a special reserve account for the exclusive benefit of customers).

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Fair value of liability associated with financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, and obligation to return cash collateral under master netting arrangements.

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Fair value of asset associated with financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, and right to receive cash collateral under master netting arrangements.

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Fair value of firm holdings in corporate fixed income securities. Includes pledged and unpledged holdings.

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The fair value as of the balance sheet date of firm holdings in corporate stocks (common and preferred), stock options, warrants and any other financial instrument which represents, or provides the ability to obtain, ownership rights in a corporation. Includes both pledged (to counterparties as collateral for financing transactions) and unpledged holdings.

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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.

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The fair value as of the balance sheet date of firm holdings in mortgages, mortgage backed securities (investment instruments that represent ownership of an undivided interest in a group of mortgages, where principal and interest from the individual mortgages are used to pay investors' principal and interest on the mortgage backed security) and asset-backed securities that are primarily paid from the cash flows of a discrete pool of receivables or other financial assets (such as credit-card receivables), either fixed or revolving, that by their terms convert into cash within a finite time period. Includes both pledged (to counterparties as collateral for financing transactions) and unpledged holdings.

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The fair value as of the balance sheet date of firm holdings in fixed income obligations issued by foreign governments. Includes both pledged (to counterparties as collateral for financing transactions) and unpledged holdings.

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The fair value as of the balance sheet date of firm holdings in private equity, mezzanine, venture capital, merchant banking, real estate and special situations investments. Includes both pledged (to counterparties as collateral for financing transactions) and unpledged holdings.

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The fair value as of the balance sheet date of firm holdings in fixed income obligations issued by state and local governments and authorities. Includes both pledged (to counterparties as collateral for financing transactions) and unpledged holdings.

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The fair value as of the balance sheet date of firm holdings in debt obligations issued by the US government including short-term Treasury bills, medium-term Treasury notes, and long-term Treasury bonds, as well as debt issued by agencies. Includes both pledged (to counterparties as collateral for financing transactions) and unpledged holdings.

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Fair value of obligations incurred from short sales.

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Fair value of obligations arising from corporate debt obligations sold short.

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Fair value of obligations arising from corporate equity sold short.

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

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Fair value of obligations arising from mortgages, mortgage-backed securities and asset-backed securities sold short.

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Fair value of obligations arising from foreign government debt obligations short.

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Fair value of obligations arising from US treasury and other US government and agency debt obligations sold short.

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The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

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Amount of collateralized debt obligations classified as other.

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