Fair Value Disclosures - Quantitative Information about Significant Unobservable Inputs Used in Level 3 Fair Value Measurements (Detail) $ / shares in Units, $ in Thousands	9 Months Ended		12 Months Ended
	Aug. 31, 2016 USD ($) T $ / shares	Aug. 31, 2015 USD ($)	Nov. 30, 2015 USD ($) $ / shares	May 31, 2016 USD ($)	May 31, 2015 USD ($)	Nov. 30, 2014 USD ($)
Embedded conversion option [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Instruments sold, not yet purchased, fair value | $		$ 114			$ 725	$ 693
Corporate equity securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Instruments owned, fair value | $	$ 22,195	38,502	$ 40,906	$ 48,816	20,547	20,964
Corporate debt securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Instruments owned, fair value | $	35,007	24,331	25,876	24,113	31,917	22,766
CDOs and CLOs [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Instruments owned, fair value | $	44,070	81,050	85,092	52,710	89,007	124,650
Municipal securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Instruments owned, fair value | $	27,257		0	0
RMBS [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Instruments owned, fair value | $	46,881	86,422	70,263	63,308	88,695	82,557
Commercial mortgage-backed securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Instruments owned, fair value | $	24,593	15,147	14,326	24,983	17,862	26,655
Other asset-backed securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Instruments owned, fair value | $	61,112	32,596	42,925	43,033	11,857	2,294
Loans and other receivables [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Instruments owned, fair value | $	78,457	95,399	189,289	104,399	108,756	97,258
Investments at fair value [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Instruments owned, fair value | $	85,036	$ 66,209	53,120	$ 57,765	$ 131,343	$ 53,224
Financial Instruments Owned [Member] | Derivatives [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Instruments owned, fair value | $	9,560		19,785
Financial Instruments Owned [Member] | Corporate equity securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Instruments owned, fair value | $	22,195		20,285
Financial Instruments Owned [Member] | Corporate debt securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Instruments owned, fair value | $	35,007		20,257
Financial Instruments Owned [Member] | CDOs and CLOs [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Instruments owned, fair value | $	32,832		49,923
Financial Instruments Owned [Member] | Municipal securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Instruments owned, fair value | $	27,257
Financial Instruments Owned [Member] | RMBS [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Instruments owned, fair value | $	46,881		70,263
Financial Instruments Owned [Member] | Commercial mortgage-backed securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Instruments owned, fair value | $	24,593		14,326
Financial Instruments Owned [Member] | Other asset-backed securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Instruments owned, fair value | $	61,112		21,463
Financial Instruments Owned [Member] | Loans and other receivables [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Instruments owned, fair value | $	52,216		161,470
Financial Instruments Owned [Member] | Investments at fair value [Member] | Private equity securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Instruments owned, fair value | $	30,724		7,693
Financial Instruments Sold, Not Yet Purchased [Member] | Derivatives [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Instruments sold, not yet purchased, fair value | $	$ 20,607		19,543
Financial Instruments Sold, Not Yet Purchased [Member] | Loans and other receivables [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Instruments sold, not yet purchased, fair value | $			$ 10,469
Level 3 [Member] | Financial Instruments Owned [Member] | Derivatives [Member] | Commodity Forwards [Member] | Market approach [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Discount rate/yield			47.00%
Significant Unobservable Input(s), Transaction level | $			$ 9,500
Level 3 [Member] | Financial Instruments Owned [Member] | Derivatives [Member] | Commodity Forwards [Member] | Market approach [Member] | Weighted Average [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Discount rate/yield			0.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Derivatives [Member] | Unfunded commitment [Member] | Market approach [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Constant default rate/Credit spread			2.98%
Level 3 [Member] | Financial Instruments Owned [Member] | Derivatives [Member] | Unfunded commitment [Member] | Comparable pricing [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Comparable bond or loan price			$ 100
Level 3 [Member] | Financial Instruments Owned [Member] | Derivatives [Member] | Total return swaps [Member] | Comparable pricing [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Comparable bond or loan price	$ 100
Level 3 [Member] | Financial Instruments Owned [Member] | Derivatives [Member] | Total return swaps [Member] | Comparable pricing [Member] | Minimum [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Comparable bond or loan price			91.7
Level 3 [Member] | Financial Instruments Owned [Member] | Derivatives [Member] | Total return swaps [Member] | Comparable pricing [Member] | Maximum [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Comparable bond or loan price			92.4
Level 3 [Member] | Financial Instruments Owned [Member] | Derivatives [Member] | Total return swaps [Member] | Comparable pricing [Member] | Weighted Average [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Comparable bond or loan price			$ 92.1
Level 3 [Member] | Financial Instruments Owned [Member] | Derivatives [Member] | Credit default swaps [Member] | Market approach [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Constant default rate/Credit spread	2.65%
Level 3 [Member] | Financial Instruments Owned [Member] | Derivatives [Member] | Interest rate swaps [Member] | Market approach [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Constant default rate/Credit spread	8.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Corporate equity securities [Member] | Market approach [Member] | Minimum [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Underlying stock price (in dollars per share)	$ 3
Level 3 [Member] | Financial Instruments Owned [Member] | Corporate equity securities [Member] | Market approach [Member] | Maximum [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Underlying stock price (in dollars per share)	$ 75
Level 3 [Member] | Financial Instruments Owned [Member] | Corporate equity securities [Member] | Non-exchange traded securities [Member] | Market approach [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), EBITDA multiple			4.4
Significant Unobservable Input(s), Transaction level (in dollars per share)			$ 1
Level 3 [Member] | Financial Instruments Owned [Member] | Corporate equity securities [Member] | Non-exchange traded securities [Member] | Market approach [Member] | Minimum [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), EBITDA multiple	5.1
Significant Unobservable Input(s), Underlying stock price (in dollars per share)			5
Level 3 [Member] | Financial Instruments Owned [Member] | Corporate equity securities [Member] | Non-exchange traded securities [Member] | Market approach [Member] | Maximum [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), EBITDA multiple	16.3
Significant Unobservable Input(s), Underlying stock price (in dollars per share)			102
Level 3 [Member] | Financial Instruments Owned [Member] | Corporate equity securities [Member] | Non-exchange traded securities [Member] | Market approach [Member] | Weighted Average [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), EBITDA multiple	12.1
Significant Unobservable Input(s), Underlying stock price (in dollars per share)	$ 15		19
Level 3 [Member] | Financial Instruments Owned [Member] | Corporate equity securities [Member] | Non-exchange traded securities [Member] | Comparable pricing [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Underlying stock price (in dollars per share)	$ 218
Significant Unobservable Input(s), Discount factor	60.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Corporate equity securities [Member] | Non-exchange traded securities [Member] | Present value [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Average silver production | T	783
Level 3 [Member] | Financial Instruments Owned [Member] | Corporate debt securities [Member] | Market approach [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Transaction level (in dollars per share)			$ 59
Level 3 [Member] | Financial Instruments Owned [Member] | Corporate debt securities [Member] | Market approach [Member] | Minimum [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Price	$ 30
Level 3 [Member] | Financial Instruments Owned [Member] | Corporate debt securities [Member] | Market approach [Member] | Maximum [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Price	100
Level 3 [Member] | Financial Instruments Owned [Member] | Corporate debt securities [Member] | Market approach [Member] | Weighted Average [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Price	$ 65
Level 3 [Member] | Financial Instruments Owned [Member] | Corporate debt securities [Member] | Convertible bond model [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Discount rate/yield	9.00%		86.00%
Significant Unobservable Input(s), Volatility	40.00%
Level 3 [Member] | Financial Instruments Owned [Member] | CDOs and CLOs [Member] | Discounted cash flows [Member] | Minimum [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Constant prepayment rate	0.00%		5.00%
Significant Unobservable Input(s), Constant default rate/Credit spread	2.00%		2.00%
Significant Unobservable Input(s), Loss severity	25.00%		25.00%
Significant Unobservable Input(s), Yield	3.00%		6.00%
Level 3 [Member] | Financial Instruments Owned [Member] | CDOs and CLOs [Member] | Discounted cash flows [Member] | Maximum [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Constant prepayment rate	20.00%		20.00%
Significant Unobservable Input(s), Constant default rate/Credit spread	7.00%		8.00%
Significant Unobservable Input(s), Loss severity	75.00%		90.00%
Significant Unobservable Input(s), Yield	35.00%		13.00%
Level 3 [Member] | Financial Instruments Owned [Member] | CDOs and CLOs [Member] | Discounted cash flows [Member] | Weighted Average [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Constant prepayment rate	17.00%		13.00%
Significant Unobservable Input(s), Constant default rate/Credit spread	3.00%		2.00%
Significant Unobservable Input(s), Loss severity	40.00%		52.00%
Significant Unobservable Input(s), Yield	15.00%		10.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Municipal securities [Member] | Scenario analysis [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Price	$ 4
Level 3 [Member] | Financial Instruments Owned [Member] | RMBS [Member] | Discounted cash flows [Member] | Minimum [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Constant prepayment rate	0.00%		0.00%
Significant Unobservable Input(s), Constant default rate/Credit spread	2.00%		1.00%
Significant Unobservable Input(s), Loss severity	10.00%		25.00%
Significant Unobservable Input(s), Yield	3.00%		1.00%
Level 3 [Member] | Financial Instruments Owned [Member] | RMBS [Member] | Discounted cash flows [Member] | Maximum [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Constant prepayment rate	25.00%		50.00%
Significant Unobservable Input(s), Constant default rate/Credit spread	50.00%		9.00%
Significant Unobservable Input(s), Loss severity	100.00%		70.00%
Significant Unobservable Input(s), Yield	9.00%		9.00%
Level 3 [Member] | Financial Instruments Owned [Member] | RMBS [Member] | Discounted cash flows [Member] | Weighted Average [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Constant prepayment rate	6.00%		13.00%
Significant Unobservable Input(s), Constant default rate/Credit spread	4.00%		3.00%
Significant Unobservable Input(s), Loss severity	55.00%		39.00%
Significant Unobservable Input(s), Yield	5.00%		6.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Commercial mortgage-backed securities [Member] | Discounted cash flows [Member] | Minimum [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Yield	6.00%		7.00%
Significant Unobservable Input(s), Cumulative loss rate	1.00%		2.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Commercial mortgage-backed securities [Member] | Discounted cash flows [Member] | Maximum [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Yield	12.00%		30.00%
Significant Unobservable Input(s), Cumulative loss rate	70.00%		63.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Commercial mortgage-backed securities [Member] | Discounted cash flows [Member] | Weighted Average [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Yield	9.00%		16.00%
Significant Unobservable Input(s), Cumulative loss rate	25.00%		23.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Other asset-backed securities [Member] | Market approach [Member] | Minimum [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Price	$ 33
Level 3 [Member] | Financial Instruments Owned [Member] | Other asset-backed securities [Member] | Market approach [Member] | Maximum [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Price	70,000,000
Level 3 [Member] | Financial Instruments Owned [Member] | Other asset-backed securities [Member] | Market approach [Member] | Weighted Average [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Price	$ 39,000,000
Level 3 [Member] | Financial Instruments Owned [Member] | Other asset-backed securities [Member] | Discounted cash flows [Member] | Minimum [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Constant prepayment rate	0.00%		6.00%
Significant Unobservable Input(s), Constant default rate/Credit spread	0.00%		3.00%
Significant Unobservable Input(s), Loss severity	0.00%		55.00%
Significant Unobservable Input(s), Yield	3.00%		7.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Other asset-backed securities [Member] | Discounted cash flows [Member] | Maximum [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Constant prepayment rate	55.00%		8.00%
Significant Unobservable Input(s), Constant default rate/Credit spread	9.00%		5.00%
Significant Unobservable Input(s), Loss severity	100.00%		75.00%
Significant Unobservable Input(s), Yield	15.00%		22.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Other asset-backed securities [Member] | Discounted cash flows [Member] | Weighted Average [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Constant prepayment rate	24.00%		7.00%
Significant Unobservable Input(s), Constant default rate/Credit spread	6.00%		4.00%
Significant Unobservable Input(s), Loss severity	85.00%		62.00%
Significant Unobservable Input(s), Yield	12.00%		18.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Other asset-backed securities [Member] | Over-collateralization [Member] | Minimum [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Over Collateralization Percentage	117.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Other asset-backed securities [Member] | Over-collateralization [Member] | Maximum [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Over Collateralization Percentage	125.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Other asset-backed securities [Member] | Over-collateralization [Member] | Weighted Average [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Over Collateralization Percentage	118.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Loans and other receivables [Member] | Market approach [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), EBITDA multiple	3.6	10.0
Level 3 [Member] | Financial Instruments Owned [Member] | Loans and other receivables [Member] | Market approach [Member] | Minimum [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Discount rate/yield	2.00%
Significant Unobservable Input(s), Yield			2.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Loans and other receivables [Member] | Market approach [Member] | Maximum [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Discount rate/yield	3.00%
Significant Unobservable Input(s), Yield			17.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Loans and other receivables [Member] | Market approach [Member] | Weighted Average [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Discount rate/yield	3.00%
Significant Unobservable Input(s), Yield			12.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Loans and other receivables [Member] | Comparable pricing [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Comparable bond or loan price	$ 98
Level 3 [Member] | Financial Instruments Owned [Member] | Loans and other receivables [Member] | Comparable pricing [Member] | Minimum [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Comparable bond or loan price			$ 99
Level 3 [Member] | Financial Instruments Owned [Member] | Loans and other receivables [Member] | Comparable pricing [Member] | Maximum [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Comparable bond or loan price			100
Level 3 [Member] | Financial Instruments Owned [Member] | Loans and other receivables [Member] | Comparable pricing [Member] | Weighted Average [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Comparable bond or loan price			$ 99.7
Level 3 [Member] | Financial Instruments Owned [Member] | Loans and other receivables [Member] | Present value [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Average silver production | T	783
Level 3 [Member] | Financial Instruments Owned [Member] | Loans and other receivables [Member] | Scenario analysis [Member] | Minimum [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Estimated recovery percentage	6.00%		6.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Loans and other receivables [Member] | Scenario analysis [Member] | Maximum [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Estimated recovery percentage	82.00%		100.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Loans and other receivables [Member] | Scenario analysis [Member] | Weighted Average [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Estimated recovery percentage	44.00%		83.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Investments at fair value [Member] | Private equity securities [Member] | Market approach [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Transaction level (in dollars per share)	$ 250		$ 64
Significant Unobservable Input(s), Enterprise value | $			$ 5,200
Level 3 [Member] | Financial Instruments Sold, Not Yet Purchased [Member] | Commercial Loan [Member] | Comparable pricing [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Comparable bond or loan price			$ 100
Level 3 [Member] | Financial Instruments Sold, Not Yet Purchased [Member] | Derivatives [Member] | Equity options [Member] | Option model [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Volatility	45.00%		45.00%
Level 3 [Member] | Financial Instruments Sold, Not Yet Purchased [Member] | Derivatives [Member] | Equity options [Member] | Default rate [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Default probability	0.00%		0.00%
Level 3 [Member] | Financial Instruments Sold, Not Yet Purchased [Member] | Derivatives [Member] | Unfunded commitment [Member] | Market approach [Member] | Minimum [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Discount rate/yield	3.00%		3.00%
Level 3 [Member] | Financial Instruments Sold, Not Yet Purchased [Member] | Derivatives [Member] | Unfunded commitment [Member] | Market approach [Member] | Maximum [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Discount rate/yield	56.00%		10.00%
Level 3 [Member] | Financial Instruments Sold, Not Yet Purchased [Member] | Derivatives [Member] | Unfunded commitment [Member] | Market approach [Member] | Weighted Average [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Discount rate/yield			10.00%
Significant Unobservable Input(s), Comparable bond or loan price	$ 0.54
Level 3 [Member] | Financial Instruments Sold, Not Yet Purchased [Member] | Derivatives [Member] | Unfunded commitment [Member] | Discounted cash flows [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Constant prepayment rate			20.00%
Significant Unobservable Input(s), Constant default rate/Credit spread			2.00%
Significant Unobservable Input(s), Loss severity			25.00%
Significant Unobservable Input(s), Yield			11.00%
Level 3 [Member] | Financial Instruments Sold, Not Yet Purchased [Member] | Derivatives [Member] | Unfunded commitment [Member] | Comparable pricing [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Comparable bond or loan price	98
Level 3 [Member] | Financial Instruments Sold, Not Yet Purchased [Member] | Derivatives [Member] | Unfunded commitment [Member] | Comparable pricing [Member] | Minimum [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Comparable bond or loan price			$ 79
Level 3 [Member] | Financial Instruments Sold, Not Yet Purchased [Member] | Derivatives [Member] | Unfunded commitment [Member] | Comparable pricing [Member] | Maximum [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Comparable bond or loan price			100
Level 3 [Member] | Financial Instruments Sold, Not Yet Purchased [Member] | Derivatives [Member] | Unfunded commitment [Member] | Comparable pricing [Member] | Weighted Average [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Comparable bond or loan price			82.6
Level 3 [Member] | Financial Instruments Sold, Not Yet Purchased [Member] | Derivatives [Member] | Total return swaps [Member] | Comparable pricing [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Comparable bond or loan price	$ 100
Level 3 [Member] | Financial Instruments Sold, Not Yet Purchased [Member] | Derivatives [Member] | Total return swaps [Member] | Comparable pricing [Member] | Minimum [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Comparable bond or loan price			91.7
Level 3 [Member] | Financial Instruments Sold, Not Yet Purchased [Member] | Derivatives [Member] | Total return swaps [Member] | Comparable pricing [Member] | Maximum [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Comparable bond or loan price			92.4
Level 3 [Member] | Financial Instruments Sold, Not Yet Purchased [Member] | Derivatives [Member] | Total return swaps [Member] | Comparable pricing [Member] | Weighted Average [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Comparable bond or loan price			$ 92.1
Level 3 [Member] | Financial Instruments Sold, Not Yet Purchased [Member] | Derivatives [Member] | Variable funding note swaps [Member] | Discounted cash flows [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Constant prepayment rate	20.00%
Significant Unobservable Input(s), Constant default rate/Credit spread	2.00%
Significant Unobservable Input(s), Loss severity	25.00%
Significant Unobservable Input(s), Yield	14.00%